Lake Xochimilco is an ancient endorheic lake, located in the present-day Borough of Xochimilco in southern Mexico City. It is the last remaining habitat of the axolotl.

An endorheic lake is a collection of water within an endorheic basin, or sink, with no evident outlet. Endorheic lakes are generally saline as a result of being unable to get rid of solutes left in the lake by evaporation. These lakes can be used as indicators of anthropogenic change, such as irrigation or climate change, in the areas surrounding them. Lakes with subsurface drainage are considered cryptorheic.