The device took the name 'LONA' from the initial letters of Lodrino and the final letters of Osogna. The location was chosen because of the morphology of the Ticino valley, which at this point has a very narrow valley floor, while the mountain sides are very steep. The LONA barrage made it possible to halt the advance of enemy troops from the south towards the Lukmanier and Gotthard passes.

The construction of the LONA Line began in 1939 and was completed in 1943. The main work was the Lodrino-Osogna infantry position, consisting of infantry forts and the V-shaped anti-tank barrage. A system of road and rail mines, shelters and weapon positions completed the device along the Boggera, in the rock face above the village of Lodrino and along the Lodrino riverbed. Artillery support was provided by the blockhouses located north of the main device, along the Mairano-Mondascia line (4 in the Mairano area and 4 in the Mondascia area). Completing the Line was the military airfield at Lodrino, built in 1940 for possible air combat use or support to ground troops.

The construction of the LONA Line began in 1939 and was completed in 1943. The main work was the Lodrino-Osogna infantry position, consisting of infantry forts and the V-shaped anti-tank barrage. A system of road and rail mines, shelters and weapon positions completed the device along the Boggera, in the rock face above the village of Lodrino and along the Lodrino riverbed. Artillery support was provided by the blockhouses located north of the main device, along the Mairano-Mondascia line (4 in the Mairano area and 4 in the Mondascia area). Completing the Line was the military airfield at Lodrino, built in 1940 for possible air combat use or support to ground troops.

After the Second World War, the defence apparatus was strengthened through the construction of a fortress mine launcher emplacement and numerous prefabricated concrete shelters.

The artillery and infantry works represented at 'Fort Mondascia' (11, 12) are the prelude or conclusion to any visit to the LONA Line. Along the route through the anti-tank barrage, the forts "Vergio" (03), built under rock as the western abutment of the barrage, the fort "Mairano" (09), which can be visited on request, the fort "Chiesa" (04) under rock and the armoured fort "Bunker Grande" (01), the only one remaining of three identical works, are of absolute interest.