This body of water, with an area of forty-three hectares, is located in an urban area in the department of Val-d'Oise, eleven kilometres north of Paris. It is included in its entirety in the perimeter of the commune of Enghien-les-Bains, which was born on its shores in the 19th century, following the discovery of the most sulphurous hot springs in France. Frozen in February 2021, the birds walk on water!