Department site (over 20ha). Site belongs to the French Coastal Conservation Agency and is a listed 'espace remarquable de Bretagne' (Brittany area of special interest) and a Trégor-Goëlo Natura 2000 site. The 'Maison du Sillon' (Sillon Discovery Centre) is open year round (see opening times for the respective periods on the Tourist Office's website) and features various exhibitions on the fauna and flora. Guided tours available to everyone (birdwatching, tide marks, flora and fauna), year round by appointment. Please contact Julien Houron on 06 37 68 48 99 or 02 96 16 54 67. The 'sillon' (strip of land) was once linked to the islets of Olonne and is constantly on the move, evolving with the movements of the tide, sand and pebbles, like a mineral tongue waving in the water.