Westerplatte is a long peninsula at the entrance to the harbour. When Gdańsk became a free city after WWI, Poland was permitted to maintain a post at this location, at the tip of the port zone. It served both trading and military purposes and had a garrison to protect it. WWII broke out here at dawn on 1 September 1939, when the German battleship Schleswig-Holstein began shelling the Polish guard post. The garrison, which numbered just 182 men, held out for seven days before surrendering.
The site is now a memorial, with some of the ruins left as they were after the bombardment, plus a massive monument put up in memory of the defenders.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.