8 Osowiec-Twierdza, Goniądz, 19-110
The Osowiec Fortress was built by the Russians in the years 1882-1915 in the narrowing of the Biebrza valley. It consists of four forts. Currently, out of four forts, only two are in working order - the Central Fort and the Swedish Fort. The remaining forts were destroyed during the hostilities and it is very dangerous to enter them. The fortress was one of the few that has never been conquered. Visiting the fortress is possible only with a certified guide. During the tour, visitors will see the weapons that were used in combat, the uniforms of soldiers, rifles and cannons with which the fortification was equipped, and will pass through the dark corridors in the basement of the fortress. An educational path has been created around the fortress. Walking along the path, visitors can see the powder magazine, cannons and the ruins of the moat and fortifications. Most of the route runs through a pine forest and a variety of vegetation that covers the bunkers. On October 9, 1998, the Osowiec Fortress was entered in the register of monuments.