Follow the discovery trail which leads to this natural amphitheatre, a mineral phenomenon carved by nature. With the sinking of the Pyrenees five million years ago, this former hill became a sand circle. Note the sibyl, an imposing stack straight out of a fairytale (a column of soft rock eroded by rain topped by an agglomeration of shingle). Head west towards Montalba. A viewpoint provides a panorama over the landscape to Ille-sur-Têt on the horizon.