Lower battery of Oscar-Fredriksborg fort

But by in the middle of the 19 AD Vaxholm Citadel fortifications become obsolete and it was decided to unlock the Oxdupet strait and to build a modern fort here. The construction started in 1867. Fort consists of two batteries - Upper and Lower, connected by an underground tunnel of 300 meters length. Armament of the fort consists of 240 mm long-barreled guns - 11 pcs, 120 mm guns -10 pcs , 80 mm guns - 7 pcs, 50 mm guns - 8 pcs. Considerable defensive power!