Visby's 3km of ramparts, partly built by the water and partly inland, are punctuated with numerous towers and gateways. The wall by the sea, 5.30m in height, runs along the coast and dates from the 13C. Pierced by gateways, it also features a 12C powder tower from where the old port (now a park) could be observed. The inland wall, 6m high and crenellated, had a gallery for archers and three gateways: Norderport (view over Visby), Österport and Söderport. 27 of the original 29 towers are still standing.