Carteia was a Phoenician and Roman town at the head of the Bay of Gibraltar in Spain. According to Strabo, it was founded around 940 BC as the trading settlement. The town's strategic location meant that it played a significant role in the wars between Carthage and the Roman Republic in the 2nd and 3rd centuries BC. It may have been the site of Hamilcar's landing with his army and elephants in 237 BC, and in 206 BC the Carthaginian admiral Adherbal retreated there with the remnants of his fleet after being defeated by Gaius Laelius in the Battle of Carteia. Around 190 BC, the town was captured by the Romans.
The Colonia Libertinorum Carteia (Freedmen's Colony of Carteia) prospered for another 580 years under Roman rule. It grew to become a substantial city which served as a centre for the export of local wines, shipped in amphorae fired in large kilns found on the site, and the manufacture of garum fish sauce.
Little is known of the remainder of Carteia's Roman history, but it appears to have been sacked by the Visigoths around 409 AD, by which time it was probably already in decline. Nonetheless, archaeological evidence shows that urban life continued there into the medieval period. The foundations of an early Christian basilica have been found, a Visigothic necropolis exists near one of the Roman temples, and Byzantine remains discovered at the site show its continued occupation when Carteia was incorporated into the Byzantine province of Spania during the 6th-7th centuries.
The area around Carteia is now heavily industrialised. The site of Carteia is surrounded on three sides by an oil refinery. However, the main urban area has been preserved and can be visited. A number of significant structures can still be seen, including the original Carthaginian city gate, a monumental sandstone flight of steps leading down to what was possibly the forum, a large temple, a number of houses and an extensive Roman baths. The 16th century Torre de Rocadillo can also be seen. The Carteia Archaeological Museum in San Roque displays archaeological finds from the site.
References: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.