Ellenabbens fort

Ellenabben Fort, also called Gamla Ellenabben (Old Ellenabben) was completed in 1904. It was built as a joined-up sunken shaft whose walls were cast and bricked over, topped with a concrete roof. The fort has been compared to a permanent coastal defence ship with its long side facing the entrance to Karlskrona from the sea.

Until 1935, the fort was armed with three 25 cm double cannons in gun turrets, which were then replaced by two 57 mm canons. After 1958 the fort was only used as an anti-aircraft post.

Source: http://fortsweden.com/objects.php?id=50d2ce670a5603.23980014