The Pièce d'Eau des Suisses is a large rectangular lake at the south end of the formal gardens, dug between 1679 and 1682 by the Swiss Guards regiment — hence the name. It covers about 14 hectares and was the largest earthwork project in the creation of the Versailles gardens, requiring the draining of a swamp and the removal of enormous quantities of soil.
The lake is quieter and less visited than most of the palace complex, reached by walking south from the Orangerie. There are no fountains here, no sculptures, and relatively few tourists: just a large stretch of water with the Orangerie at one end and flat meadowland beyond. It makes a good walk if you want to escape the crowds, and the view from the south bank looking back toward the palace, with the Orangerie in the middle distance, is one of the better landscape views at Versailles.
The Swiss Guards who dug the lake suffered badly from malaria during the construction — the swamp they were draining bred mosquitoes in enormous numbers. Several hundred men died in the process. The lake is one of the places where the enormous human cost of creating Versailles is most directly present.