Lac inférieur, Reservoir in bois de Boulogne, Paris, France.

Lac Inférieur is an artificial lake in the Bois de Boulogne with two islands connected by a suspension bridge. Tall trees line the shore, and several paths wind around the water.

The lake was created in 1854 under Napoleon III as part of a major park renovation. Engineer Adolphe Alphand designed the water system to transform the area into a green retreat.

The two islands are reached by rowing boat from the shore; the larger one holds a restaurant, the smaller a pavilion. Both were laid out when the lake was dug in 1854, and the boat crossing is part of the visit.

A path of about 3 kilometers circles the entire lake and works for walking, jogging, and cycling. The route is open year-round and offers spots to rest along the way.

The lake feeds the Longchamp and Bagatelle streams and receives water pumped from the Seine at Boulogne, part of Adolphe Alphand's 1850s system of pumps, pipes and cascades that still supplies the Bois de Boulogne.