Just above the rocky Fornelos Beach, there are several prehistoric salt pans, which resemble large troughs carved into the granite rock at high tide level. These irregularly shaped cavities were carved out by ancient populations to collect seawater and produce salt through natural evaporation. Each basin has a rim to prevent the water from spreading and thus favour the concentration of salt during drying in the sun. Most of these structures date from the Iron Age and are part of an archaeological complex for the extraction of sea salt.