battlements castle cold defence Edinburgh fort fortress garrison impregnable rock scotland snow snowy stone stronghold wall walls winter ancient arch architecture autumn castles defense door fall gate medieval protection rocks secure security trap trapdoor bricks defend defender framlingham mortar old stones Suffolk texture tower croatia europe flag fortification historic Rijeka turret city coast fortifications Greece Greek harbor harbour historical homes houses mediterranean nafplio sea town view chalk cobble defensive England flint Great Britain kent military protect ruins acre Akko buildings Israel urban water cannon corroded corrosion decay gun iron rusty weapon