Fortress.

Keywords:

river, wave, waves, sky, summer, morning, nature, horizon, season, tree, trees, outdoors, outdoor, horizontal, water, reflection, fort, fortress, tower, travel, ancient, architecture, building, built, castle, citadel, defending, dome, Europe, exterior, famous, heritage, historic, history, landmark, medieval, military, monument, obsolete, old, past, protection, protective, rock, ruin, safety, security, stone, strength, stronghold, structure, tourism, Ukraine, vacation, view, visit, wall,