It overlooks the town from the middle of a small wood. It was the castle keep, built to a very rare, four-petalled rose design, and its name comes from the old French word «guigner» meaning «watch», since it was used as a watchtower. Taken by Henry IV in 1589, the inhabitants asked for its demolition, as they were tired of the ceaseless combats to seize the keep. Good King Henry did not do things by halves: the cracks caused by the explosion of the barrels of gunpowder can still be seen today.