Ismantrop is an ancient fortress, which was used probably between years 300-500 AD. The ringfort consists of a limestone wall approximately 300 meters long and has nine gates. Inside the ringfort were 95 houses arranged in 12 blocks around a central open area with a circular building. Ismantorp is the largest and probably the oldest of the ringforts on Öland.
The first written description of Ismantorp dates back to the year 1634. Renowned botanist Carl von Linné, as well as other travellers and scholars, paid attention to the fortress. Researchers have tried to determine the fortress's age, function and history since the 19th century. Its well-preserved walls distinguish the fortress, as do the central building's unusual location on a ground elevation, the 88 visible house foundations and the nine gates.
Theories of Ismantorp's function differ widely. The fortifications suggest a defensive purpose, but its many gates make is difficult to defend. Ismantorp fortress has been compared to large Slavic castles that were both protective fortress and religious sanctuaries. Other researchers view the fortress as an integrated part of a united defence of the island of Öland.
Ismantorp, which today is surrounded by marshes in the Mittlandskogen forest, is an archaeological enigma as well as a popular place to visit.References:
The Château d'Olhain is probably the most famous castle of the Artois region. It is located in the middle of a lake which reflects its picturesque towers and curtain walls. It was also a major stronghold for the Artois in medieval times and testimony to the power of the Olhain family, first mentioned from the 12th century.
The existence of the castle was known early in the 13th century, but the present construction is largely the work of Jean de Nielles, who married Marie d’Olhain at the end of the 15th century.
The marriage of Alix Nielles to Jean de Berghes, Grand Veneur de France (master of hounds) to the King, meant the castle passed to this family, who kept it for more than 450 years. Once confiscated by Charles Quint, it suffered during the wars that ravaged the Artois. Besieged in 1641 by the French, it was partly demolished by the Spaniards in 1654, and finally blown-up and taken by the Dutch in 1710. Restored in 1830, it was abandoned after 1870, and sold by the last Prince of Berghes in 1900. There is also evidence that one of the castles occupants was related to Charles de Batz-Castelmore d'Artagnan, the person Alexandre Dumas based his Three Musketeers charictor d'Artagnan on.
During the World War I and World War II, the castle was requisitioned first by French troops, then Canadian and British soldiers. The current owner has restored the castle to its former glory.