The Genoese Citadel is the main part of the town of Calvi, and its most important historical monument. It was a military outpost in the 15th century that helped guard the city against attacks from Franco-Turkish raiders to Anglo-Corsican armies. Inside the battlements, don’t miss the well-proportioned Caserne Sampiero, a military barracks that once served as the Genoese administration's seat of power, and the 13th-century Cathédrale St-Jean Baptiste, whose most celebrated relic is the ebony Christ des Miracles, credited with saving Calvi from Saracen invasion in 1553.
The citadel sits high above Calvi port from where it towers over the sea. From up here you get some great views of the coast and harbour.
Carlsten is a stone fortress built on the orders of King Carl X of Sweden following the Treaty of Roskilde, 1658 to protect the newly acquired province of Bohuslän from hostile attacks. The site of Marstrand was chosen because of its location and its access to an ice free port. Initially a square stone tower was constructed, but by 1680 it was reconstructed and replaced by a round shaped tower. Successive additions to the fortress were carried out, by the inmates sentenced to hard labour, until 1860 when it was reported finished. The fortress was decommissioned as a permanent defense installation in 1882, but remained in military use until the early 1990s.
The fortress was attacked and sieged twice falling into enemy hands. In 1677 it was conquered by Ulrik Frederick Gyldenløve, the Danish military commander in Norway and in 1719 by the Norwegian Vice-Admiral Tordenskjold. At both occasions the fortress was returned to Swedish control through negotiations and treaties.