The fort of Oga is located at an altitude of about 1730 meters above sea level in a place that was identified with the toponym of Dossaccio. Originally it should have been built in the early 1900s at Le Motte, but it was then built here between 1908 and 1914 to defend the main Alpine passes, thinking about a possible conflict with Austria and a possible enemy crossing from the nearby Switzerland. From this position above Bormio, all the main access routes to “Alta Valtellina”, from the Foscagno pass to the Fraele valleys, from the Stelvio-Umbrail pass, to the Valfurva paths could easily be taken.
Since 1938 the fort is named after Captain Corrado Venini, Gold Medal for Military Valor for having fallen in combat during the Great War during operations to contrast the Strafexpedition unleashed in Trentino in May 1916. Curiously his son Giulio will follow the same tragic fate, falling into combat in Greece in 1941.
The road that leads to the foot of the fort was built precisely on the occasion of its construction to replace the old mule track, as a suitable transport route was necessary in order to transport materials, some of which locally sourced, like the stone of the Cadolena valley, the Adda river sand, the good quality lime obtained from the dolomite bormina stone and the iron of the historical Premadio ovens.
The access road to the fort is identifiable with the stone bridge (1) that allows you to cross the peat bog and leads inside the Paluaccio Nature Reserve, established in 1983.
Beyond the bridge, on the left, there is one of the buildings belonging to the fort (3), currently disused, but destined to become the “gate of the park of the fort of Oga”, a welcoming structure for visitors to the fort and the nature reserve .
From here, continuing on the right, we begin the climb that leads to the fort (5) and after a few dozen meters, on the left, we meet the so-called “casermetta” (6), built in 1935 which was originally a stone cabin, where a border guard department was located. The building, once restored, has become the “home of the nature reserve” and conferences and educational activities take place there. Looking towards the valley, one can see another building belonging to the compendium and originally intended for the military housing (7).
Returning to the ascent, we find, after the first bend, a postern (8), that is a small secret door that can be used as a secondary access, as an escape route in case of siege or as an access to transport the powders to the powder magazine, to which it is also connected. At the next hairpin bend we meet the “sentinel path”, a roundabout path that encloses the defense structures of the fort made up of the moat and the system of cross-barriers that run along the entire perimeter; along the path you can see most of the defenses still standing.
Going along the final part of the climb, you reach the square in front of the entrance to the fort (9) that leads to the access portal.
Once through the entrance door, you walk on the original sliding bridge, controlled by the guardhouse, located on the right-hand side, from which the soldiers, in the event of an enemy attack, could activate the movement by opening the moat exposed to the soldiers with the possibility to introduce grenades by sliding them from the appropriate holes.
Now the guardhouse is used as a “shrine” with the display of some war memorabilia. However, the steering wheel, thanks to which it was possible to operate the bridge movement is still there, and, through a narrow floor hatch, it is possible to access the underlying part where the compartments and the equipment used for the mobile bridge can still be seen.
Continuing beyond the entrance hall you exit the long internal courtyard (11) from which you can access all areas of the fort.
On the southern side there are the kitchen, the food storeroom, the latrines (officers and troops), the local offices and the entrance to the underground powder magazine; on the northern one there are two entrances to the main body and, at the west end, the access road to the roof, an extremely interesting path that allows you to closely observe the moat surrounding the fort on the entire perimeter with the exception of the south west side .
Those who managed to overcome the external barbed wire meshes would have to jump from the wall to penetrate inside, with the danger of falling on the deadly chevals de frise consisting of groups of sharp points of iron placed at “porcupine” in turn connected from barbed wire, and avoid the shots of machine guns of the two disappearing machine gun turret (12) that covered the area and of the caponier jutting out on the courtyard (13), which with a pulling shot or threading fire (ie parallel to the walls aimed at striking on the side the assailants), protected the moat and the exterior of the wall.
Going up the steps in the structure you can appreciate the expanse of the four armoured gun turrets (14) and guess, observing the magnificent panorama, how the location of the fort could be strategically decisive in the framework of the territorial defense program.
Entering the main body through the western gate there are four possible route options: on the left the visit to the west caponier and to the officers’ sleeping quarters (15); on the right the corridor to which all the other rooms on the ground floor belong; to the north it is possible to access the west gun turret and the staircase leading to the upper floor. Going right along the corridor, you have the battery room followed by the room where you still can find the power generator (16).
The electricity at the service of the entire structure was produced thanks to the energy of the naphtha engine positioned in this room that moved the dynamo connected to it. In order not to signal to the enemy the position of the fort, the thick black smoke produced by the combustion of the fuel was filtered through the system for smoke elimination located in the courtyard (17): a cistern containing water in which the fumes deposited the soot, allowing a purification of the smoke that escaped into the air with a white color.
Along the corridor are located the armory, the barrack rooms, the infirmary and the bullets warehouses. Some of these rooms, having no original furnishings, were set up with photographic reproductions (18) combined with emblematic phrases associated with various themes.
At the end of the corridor, a steep stairway leads to the east caponier and a hallway to the left leads to the disappearing east gun turret (19) which, like its western counterpart, housed a Gardner machine gun with a 2 km radius; its function was to defend the fort from a possible enemy infantry attack. The turret, rotating manually, could beat the entire perimeter of the moat and the reticulates around the fort. The tower could be lowered until it disappeared into the ground, hence the term “disappearing”.
The upper floor of the fort is characterized by the presence of the large access corridor (21) from which you climb to access the wells for cannons covered by armored domes that were built in the factory of Pozzuoli of the British factory Armstrong. They rested on large ball bearings and rotated 360 degrees with the cannon; they are of the “light” type, that is, only 40 mm thick instead of 140, therefore with limited resistance. The choice of these domes was probably due to the fact that the fort was in a very secluded position with respect to the shooting of enemy artillery; in fact the fort was never hit, being out of the maximum range of the Austrian pieces.
It should be noted that the positioning and removal of the cannon barrel could take place without dismantling the dome. The thousands of kilograms of the fire mouth were slid through the internal staircase that connects the access corridor and the dome (22), using the rings embedded in the walls, winches, ropes, mules and men.
The other rooms on the floor were used as munitions stores and, in a secluded position in the north-east corner, the control room (23) from which a complex communications system with copper pipes (intercom) started, allowing communication with each munitions room and every turret.
For long distance communications and connections between the fort and the outside and with the command located further downstream at Bagni di Bormio, a special telephone line was set up that branched further towards the Italian peaks up to the Trafoi peak, from which the Italian lookouts communicated to the fort shooting adjustments for artillery.