At Colico, where Lake Como ends and the Valtellina and the Valchiavenna open up, there is a hill with four guns on its roof. It is Forte Montecchio Nord, built between 1912 and 1914 to stop an army that might come down from Switzerland or from the Stelvio Pass. That invasion (fortunately) never came.

The guns, on the other hand, are still in place, inside steel domes that rotate on themselves, and in war they fired only once: on 27 April 1945, thirty years after the fort entered service, just five shots in all. The target was the German column that, that same day at Dongo, had left Mussolini in the hands of the partisans.

None of the five shots hit the mark, yet they were enough to stop it. The fort was built to bar the way to anyone coming down from the north, and the only shots it fired in war were against those who were heading back north.

Today the Montecchio Nord is a museum that can only be visited with a guide. Those who run it present it as the best-preserved fortress of the Great War in Europe, and it is often described as the only Italian fort of that period to have kept its original armament. Inside are still the barracks, the powder magazine dug into the rock, the marble electrical panels, the command room with its copper intercom.

All this has come down to us for the same reason that makes its history so strange: the Montecchio spent its two wars almost always waiting.

To understand why this very hill was chosen, you only need to look at a map. The head of Lake Como works like a funnel. From the north come down the Valchiavenna and the Valtellina, and with them the roads of five Alpine passes: the Splügen, the Maloja, the Bernina, the Stelvio and, via the Aprica, the Tonale.

They all converge on the plain where the Adda enters the lake, and from there continue along the two shores toward Como and toward Lecco, that is, toward Milan. The Montecchio Nord is one of the four rocky hills that, at the foot of Monte Legnone, overlook the Upper Lario and the mouth of the Adda, on the border between the provinces of Lecco, Como and Sondrio. From up there one controls the two valleys, the roads and the railway lines together.

That this was the gateway to Lombardy is also told by Manzoni. In chapter XXVIII of I promessi sposi, describing the descent of the Landsknechts in 1629, he writes: “Colico was the first land of the duchy that those demons invaded; they then threw themselves upon Bellano; from there they entered and spread into the Valsassina, from where they issued into the territory of Lecco.”

The Spaniards who governed Milan had already tried to close that gate. Between 1603 and 1604 the governor Pedro Enríquez de Acevedo, Count of Fuentes, the same who appears in the story of the Pesa Vegia of Bellano, had a fortress built on the nearby hill of Monteggiolo that still bears his name. It served to hinder traffic toward Chiavenna and the Valtellina and to keep the Grisons in check: the Spaniards called it the “yoke of the Grisons”, and the Grisons, because of the malarial marshes of the Adda delta in which it stood, the “tomb of the Spaniards”.

The Fuentes Fort was demolished in 1797 and today only its ruins remain. Already in 1871 the Italian military were thinking of replacing it with a modern work on top of the Montecchio, and the logic was the same as three centuries earlier: once past Colico, an army only had to reach Lecco to find in front of it a long descent to the Po.

For forty years the new fort was only talked about. In 1882 the General Staff committee rejected the project altogether: an Austrian violation of Swiss territory seemed unlikely, even though a German invasion was considered easily foreseeable.

In 1901 the Ministry of War studied more modest solutions, batteries protected by a concrete parapet at Fuentes and guns hidden in a cave on the Piona peninsula, but budget problems and diplomatic uncertainties pushed everything back.

The turning point came between 1911 and 1912. In June 1911, after some inspections along the border, the General Staff chose the Montecchio Nord, preferring it to the Montecchio Sud. The law of 23 June 1912 assigned the Ministry of War a further sixty million lire to be spent by 1918 and truly got the Frontiera Nord under way, the defensive system facing Switzerland that everyone now calls the Cadorna Line. For the Montecchio, 750,000 lire were initially allocated. The order to carry out the works is dated 8 April 1913, by December access roads and quarters were finished, and on 6 December 1914 the fort was armed and operational. It had been built in little more than a year.

When work began, Italy was still part of the Triple Alliance, signed in 1882 with Germany and Austria-Hungary, and when the fort was armed it was a neutral country: it would enter the war only on 24 May 1915. The Montecchio Nord was designed, in short, against two allies, for fear that they might pass through a neutral country. Switzerland had always respected its neutrality, but in Rome no one ruled out that it might side with Italy's enemies or even just let them through.

The suspicion was mutual: Colonel Arnold Keller, Swiss chief of staff from 1890 to 1905, had put attack plans against Italy in writing in a secret report, which can now be read in a book with an eloquent title, La frontiera contesa.

The visit starts from the bottom, at the barracks, at an altitude of 258 metres. It is a block set into the hill, built largely with San Fedelino granite, with concrete and stone walls between one and a half and two metres thick, designed to withstand direct hits from medium-calibre artillery. Between the wall and the rock runs a seventy-centimetre cavity that kept moisture away.

The troops slept in a single heated dormitory, with about forty bunks; next to it were the quartermaster's office, the infirmary, the armoury, with its rack still in place, and the command, with a large hand-painted map of the territory on the wall. On the parade ground one can still make out the garrison's bocce court.

From the barracks to the battery one climbs along a covered passage of about 140 metres, two and a half metres wide and three high, leaning against the mountain on one side and protected on the other by a metre and a half of reinforced concrete, with ten loopholes in worked granite. Halfway along, a side tunnel enters the rock: it is the powder magazine, and here every detail speaks of the fear of fire. The six explosives storerooms open staggered, so that no door faces another. The floor is wood fixed with bronze nails, which do not make sparks.

Under the vault runs a sheet of galvanised metal on which moisture condenses and then slides into gutters at the sides of the corridor. A little further on are two small rooms where fuzes and shells were armed, and their outer walls were deliberately left unfortified: in case of an accidental explosion, the blast was meant to vent outside and not inside the passage.

The battery proper is on two floors. On the ground floor are the ammunition stores, three large rooms dug into the rock, and the engine room, the heart of the fort. Electricity came from dynamos driven by internal combustion engines, four lead accumulators maintained a constant voltage of 120 volts, and the knife switches are mounted on marble panels by Ercole Marelli of Milan. A forced ventilation system brought fresh air into the rooms and drew out the fumes of the guns and engines, also because in summer temperatures under the domes could exceed forty degrees.

The fumes did not exit from above, where they would have revealed the fort's position: they were pushed into a tunnel of about fifty metres and discharged into the woods, outside the walls. Those from the engines first passed through a water tank that cooled them and turned them white, making them harder to notice.

Hand-operated hoists lifted shells and charges to the first floor, along a sixty-metre corridor onto which open the storerooms and the stairs of the four turrets. Here is the command room, where the firing data were set, that is, the type of shell, the charge, the elevation and the direction. It has an observation turret, a telephone panel and an intercom made of copper tubes to speak with the storerooms and the turrets.

In each of the four turrets is a 149-millimetre Schneider gun, model 1910, the so-called 149S. Two were built by the French firm Schneider, two in Italy under licence. The barrel is five metres forty long and on its own weighs 3,800 kilos. The piece is enclosed in a steel dome 164 millimetres thick overall, which rotates together with it on 64 rollers and lets it fire in any direction, with an elevation ranging from eight degrees below the horizon to forty-two above.

Each installation weighs more than a hundred tonnes. Each piece required six gunners, a gun captain and five servers, and the ammunition was 42-kilo grenades and 52-kilo shrapnel, launched by ballistite charges enclosed in gauze bags up to about thirteen and a half kilometres.

The installation is of naval type, adapted for land use, and the sign of it can still be seen: in the rear plate of the dome there is a hatch that serves no purpose, because it was designed for use on ships. These four are the only pieces of this kind in Italy still mounted on working rotating installations.

The system had a weak point, however. The domes have a low profile, designed to deflect direct-fire projectiles, which arrive at an angle of around thirty degrees. They were not built to withstand howitzers and mortars, which drop their shots from above at an angle greater than forty-five degrees, and of siege howitzers the Austro-Hungarian army was well supplied.

Italy entered the war on 24 May 1915, and the Montecchio Nord spent a good part of the conflict without its guns. In July, as in many other forts, the high command had them dismantled and moved to more protected and less easily located places, and on 1 August General Cadorna also had the four Perino machine guns of the close defence removed, to form field sections. Only in March 1918, when an Austrian descent was by then feared imminent, did Badoglio order the fort to be re-armed, amid serious difficulties.

In the meantime other positions had been prepared around the Montecchio: on the Legnone, on the Legnoncino and below the Castello di Vezio, above Varenna, where a 75-millimetre battery was to strike the western shore of the lake. The garrison, between thirty and forty men, almost all gunners, was never called into action. Switzerland remained neutral and Austria, which fought hard on the Stelvio, never attempted the decisive attack from that side.

Between the two wars the fort remained garrisoned and the guns were kept in working order. In the 1930s it was held by a unit of the 4th artillery regiment, and the most eventful episode of the decade dates to 1938, when guards stopped two alleged French spies near the structure. The carabinieri checked their identity: they were two tourists who had got lost. In 1939 the garrison passed to the Guardia alla frontiera and the fort was named after Aldo Lusardi, gold medal for military valour, killed in Ethiopia in 1935. For this reason it also appears in documents as Forte Lusardi.

At the outbreak of the Second World War the Montecchio was used mainly for training, and the calm of the sector was such that in 1940 many of its soldiers were hired as extras in Mario Camerini's film I promessi sposi. Thus the soldiers who guarded the road of the Landsknechts ended up on the set of the film based on the novel that had described that very road.

The enemy for which the fort had been built did arrive, in September 1943, but it did not come down from the Splügen and did not cross Switzerland. After the armistice a German unit entered the fort directly, intending to deport the garrison to Germany.

It did not do so, and the gunners were brought back to the fort to continue the garrison duty, now under the Social Republic. Allied bombing hit the area several times, so much so that the centre of Colico near the station was evacuated, but the Montecchio was never targeted. Nor did the partisans attack it: the fort actually became the base of over a hundred Italian and German soldiers employed against them.

At the end of 1944, with the Resistance now active throughout the Upper Lario, an officer of the Social Republic sent to inspect the garrison discovered a plot to hand the fort over to the partisans. Six soldiers were sentenced to death for high treason and transferred to Como, where a second trial confirmed the sentence, with the execution set for 25 April 1945. That day the general insurrection broke out, and the six were saved.

In the last months there had even been talk of making the Montecchio one of the strongpoints of the Republican Alpine Redoubt, the last line in which the RSI units were to entrench themselves. On 20 April the command of the fort passed to a German sergeant major. On the 25th the parish priest of Colico tried to persuade the garrison to surrender, without success, and on the 26th the Germans placed two machine guns pointed at the village. The same day some Italian soldiers attacked those positions and a German soldier died in the clash.

Inside, the few Italians held prisoner managed to capture some Germans and, after a brief battle, persuaded the sergeant major and the rest of the garrison to surrender. The fort passed to the National Liberation Committee of Colico.

On the morning of 27 April, on the other shore of the lake, the partisans of the 52nd Garibaldi Brigade stopped at Musso a German column retreating north. In the afternoon, during the inspection of the vehicles at Dongo, Mussolini was recognised and arrested together with the hierarchs travelling with the column, and the Germans obtained clearance to continue. In command was Hans Fallmeyer, and the column's route went up the western shore toward the head of the lake and Switzerland.

At the Montecchio, meanwhile, there was a new commander, Battista Canclini. When he sighted the column he asked the CLN of Colico for permission to open fire. There was a problem: before the surrender, the Germans had burned the firing charts, those needed to aim the guns correctly. The gunners fired anyway. Five shots were fired, and none hit its mark.

They were enough all the same. Fallmeyer, thinking he was under fire, halted the vehicles under cover of some houses and began negotiating by telephone with the partisan command. The following day, around three in the afternoon, from the Morbegno command a phone call reached the CLN of Colico: a room had to be prepared for an important meeting and a German interpreter found. At 4.10 pm in front of the Albergo Isolabella in Colico a car with a white flag stopped, and the German officer stepped out. Before beginning he wanted the sergeant major captured at the fort two days earlier to be present as well.

After a tense discussion they reached a four-point agreement, which among other things left the Germans the road to Switzerland, and the surrender was signed with the delegates of the 52nd Garibaldi Brigade and of the CLN.

After those five shots the guns fell silent for two years. They fired again in 1947, for the last time, and in front of them they had no enemy. It was the funeral of Leopoldo Scalcini, born in Colico in 1911, a lawyer and army lieutenant, who during the Resistance had commanded a partisan formation in the mountains around the village under the nom de guerre Mina.

On 30 December 1944 a unit of the Black Brigade of Como had captured him together with dozens of comrades at the Culmine di San Pietro, between the Valsassina and the Val Taleggio. The next day Scalcini was killed, and ten partisans taken with him were shot in front of the cemetery of Barzio and buried in a single grave.

In 1947 the bodies were exhumed, and Scalcini returned to Colico together with some of his men. To honour him the fort fired twenty shots toward the Legnone basin. Actually twenty-one, according to the reconstruction of Stefano Cassinelli, author of a monograph on the fort: one of the shells hit the mountain without exploding, and the shot was repeated. Since then the guns of the Montecchio have not fired again.

In the 1950s the Montecchio Nord was turned into a powder magazine, with the addition of a depot at the top of the hill, a fire-fighting system and a house for the sergeant major, and on the old bocce court a rack for the fire hydrants was installed.

It remained in service until 1981, when it was demilitarised and passed to the civil state property. In 1998 the Ministry of Finance entrusted its management to the Municipality of Colico, which after some attempts at enhancement handed it over to the Museo della Guerra Bianca in Adamello. On 17 October 2009 the fort was inaugurated as a museum.

Precisely because it never truly fought, the Montecchio preserves what in many fortifications of the same era has been lost: besides the guns and domes, the electrical system, the original fixtures and armour plating, the ventilation systems and those for the water supply. It is not a reconstruction, and one can tell from the details, such as the old water pump in front of the kitchens or the anchor points in the battery corridor that were used to replace the guns' barrels.

The fort can only be visited with a guide. In the 2026 calendar, regular openings fall on Saturdays and Sundays, with departures every hour from 10 to 5; on some days visits are afternoon-only, at 2, 3 and 4 pm, and in case of bad weather they are cancelled.

It is best to check the calendar before setting out and to arrive ten minutes before departure. Organised groups can book a visit on any day of the year, with a guide in Italian, English, French or German.

The full-price ticket costs 10 euros, the reduced ticket for young people aged 6 to 17 costs 6 euros, and children up to 5 enter free. The combined ticket with the Fuentes Fort costs 15 euros, 8 for young people. For groups the guide costs 70 euros per 25 people, in addition to the tickets.

The fort is at via alle Torri 8, ten minutes' walk from Colico station, on the line that runs from Milan through Lecco and continues toward Sondrio and Tirano. By car, from Milan and from Lecco take the SS36 to the Piona exit and then the provincial road 72 toward Colico: just after the centre and the station you pass through the railway underpass, cross viale Padania and turn into via alle Torri, which in five hundred metres leads to the entrance. Those arriving from Como or Lugano can go up the western shore to the head of the lake. For information the fort can be reached at 0341 940322.

The natural complement to the visit is the Fuentes Fort, on the hill of Monteggiolo, which tells the same idea three centuries earlier and can be visited with the combined ticket. From the Montecchio one overlooks the Pian di Spagna and Lago di Mezzola Nature Reserve, over 1,600 hectares of wetland between the mouth of the Mera and that of the Adda, important for the nesting of many bird species.

South of the village, on the Olgiasca promontory, is the Abbey of Piona, with its Romanesque church and medieval cloister. And Colico, with its lido and the wind that makes it one of the Lario's favourite destinations for kitesurfers, is the right place to end the day on the water.

The best view, however, remains the one from the fort. During the visit you step outside, next to the domes, and from up there you can see the lake, the Pian di Spagna, the mouth of the Adda and the mountains of the Valtellina and the Valchiavenna, that is, everything the Montecchio was meant to watch over. It is the same panorama the sentries had before them in 1914.