Check out the Napoleonic hilltop forts on Gdańsk’s Grodzisko Hill next to the Centrum Hewelianum science exhibition. Built 46 metres above sea level the views across the Gdańsk are awesome, and their strategic importance wasn’t lost on the Germans who installed an anti-aircraft battery up here. Close up investigation is obstructed by fences and warning signs, though you can just about make your way up the concrete observation post installed during the war.