The Dune du Pilat is the tallest sand dune in Europe, rising over 100 metres above sea level at its highest point and stretching about 2.7km along the coast south of Arcachon. It is a genuinely spectacular natural feature: from the summit you look west to the Atlantic breakers, south over an apparently endless pine forest, and north across the Bassin d'Arcachon to the Banc d'Arguin sandbank.
Getting to the top requires a climb — about 150 steps on a fixed wooden staircase, or you can scramble up the sand itself, which is harder and gets the sand into your shoes. On the seaward side, the dune plunges steeply to the beach below, and in summer this slope fills with paragliders and people careering down on foot. The beach at the base is good, though the water can be cold.
The dune draws around two million visitors a year, and in July and August the access road and car parks can be very busy. Coming early in the morning or in the evening light, when the shadows are long, makes for a considerably better experience. In shoulder season (May, June, September) you may have it nearly to yourself. From La Teste-de-Buch, the dune is about 8km by road.