A jagged coastline, fringed by reefs and spiked with rocky outcrops, is the surprising sight that surrounds the Le Gouffre site.
Over time, the landscape has been gradually transformed. Complex swell phenomena have led to accumulations of pebbles that have lengthened to form tombolos.
Tombolos are transverse bands of pebbles linking the land to islets.
At the Plougrescant site, a system of three pebble channels enclose two brackish water lagoons. These lagoons, which communicate with the marine environment via the pebble strips, are of great botanical interest.
Erosion affects rocks differently depending on their composition. Here, granite, which is less degraded, forms rocky heaps known as granite chaos.