Almost circular, Lake Servières, located in the municipality of Orcival in the Puy-de-Dôme department, is often considered one of the most beautiful lakes in the Auvergne region. It owes its shape to its location inside an ancient maar crater, at 3,943 ft (1,202 m) of altitude. Maars are the only types of volcanic craters capable of accommodating lakes as they do not consist of fragmented hence permeable volcanic materials.