Houdan Keep

Dating back to the 12th century and built on a former Merovingian burial ground, the 25 metre-high Houdan Keep, or the Donjon as people call it, rears up against the sky with its four rounded towers, as if it were ready to repel an onslaught of enemies even today.

The site – which over the years has been a watchtower, prison, and a water tower – is a magnificent testament to the town’s medieval past, and is now a listed Historical Monument. This heritage dates back to the days of the Counts of Montfort, with the tower also having links to the Duchy of Brittany and the French Royal Family.

The tour, complete with information boards on the site’s history and architecture, leads you all the way to the panoramic terrace and some incredible views over the old town and surrounding countryside.

Check out the Tour Jean sans Peur, right in the heart of Paris.