Lembecksburg was a medieval ring wall with a diameter of 95 meters and a height of ten meters. According to old lore, it was constructed in the 9th century as a stronghold against the Vikings and is named after the knight Klaus Lembeck who had allegedly been residing there as a steward of king Valdemar IV of Denmark in the 14th century. After breaking his feudal oath, though, Lembeck is said to have been besieged by the king's host. Ít is disputed though whether Lembeck ever set foot on the island. Archaeological findings on Sylt island in the late 1970s suggest, however, that the Lembecksburg and similar facilities on Sylt date back to the days of the Roman Empire.
The Château des ducs de Bretagne (Castle of the Dukes of Brittany) is a large castle located in Nantes. It served as the centre of the historical province of Brittany until its separation in 1941. It was the residence of the Dukes of Brittany between the 13th and 16th centuries, subsequently becoming the Breton residence of the French Monarchy. Today the castle houses the Nantes History Museum.
The restored edifice now includes the new Nantes History Museum, installed in 32 of the castle rooms. The museum presents more than 850 objects of collection with the aid of multimedia devices. The castle and the museum try to offer a modern vision of the heritage by presenting the past, the present and the future of the city. Night-time illuminations at the castle further reinforce the revival of the site. The 500-metre round walk on the fortified ramparts provides views not just of the castle buildings and courtyards but also of the town.