Gioia del Colle, Italy
9t
Bisceglie, Italy
1060-1070
Massafra, Italy
10th century AD
Carovigno, Italy
12th century
San Nicandro Garganico, Italy
15th century
Andrano, Italy
14th century
Torremaggiore, Italy
11th century
Torremaggiore, Italy
11th century
Canosa di Puglia, Italy
4th century AD
Brindisi, Italy
1491
Sannicandro di Bari, Italy
916 AD
Brindisi, Italy
1227
Leporano, Italy
14th century
Pulsano, Italy
1430
Monopoli, Italy
1086
Gravina in Puglia, Italy
1231
Tricase, Italy
15th century
Conversano, Italy
11th century
Apricena, Italy
11th century
Tricase, Italy
1480-1524
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.