Hanko Fortress

The island fortresses formed a triangle that protected the sea channel leading to the port of Hanko.

[1][2] The first cannon field fortress, Brunerskärin Skanssi, was built on Tulliniemi in Hanko already at the end of the 17th century.

The construction of the Hanko fortress actually began after the war of King Gustav III in 1788–1790, when it was decided to replace the temporary field fortifications built on Tulliniemi and its nearby islands with permanent fortifications protecting Hanko harbor.

The fortifications continued until the beginning of the 19th century, but the fortress remained unfinished.

[4] The furniture of the Hanko fortress is still on the islands of Gustavsvärn and Gustaf Adolf.