The Batéguier pond is a coastal lagoon of 10 acres (4 ha) located on Sainte-Marguerite Island in the Lérins archipelago. Its uncertain but ancient origin would be linked to the submersion of a quarry or a Roman port. Almost filled with silt accumulated by regressive erosion in the 1970s, the pond was cleaned from 1974 to 1982 by the National Forests Office, and today shelters protected plant species such as Ruppia maritima and Cymodocea nodosa.