Ashtamudi Kayal is a freshwater lake located in the Kollam district of Kerala. Ashtamudi means ‘eight coned’ in the local Malayalam language. The name is indicative of the lake’s topography, which is palm-shaped or octopus-shaped.

It is the second largest and deepest wetland ecosystem of Kerala, which supports around 43 marshy and mangrove species, 57 species of birds, 97 species of fish and some unique copepod species.

Ashtamudi Kayal is included in the list of wetlands of international importance and is designated as a Ramsar Site.