Walking towards a passage to a medieval castle, a ancient fortress, on a cold autumn day, on Suomenlinna military island, in Helsinki, Uusimaa, Finland

fortification suomenlinna catacombs tunnel wall fort cellar sveaborg fortress ruins ruin entrance gate medieval dungeon basement passage castle underground stone ancient abandoned tower landscape building tourism granite brick historical construction architecture old history door travel suomi finland main historic city creepy wine sea mystical horror helsinki dark black dirty