This is a unique reef formed by carbonate bioherms in a freshwater lake. The reefs are located in Green Lakes State Park , New York near Syracuse. This lake is one of the most studied meromictic lakes in the world. A meromictic lake is a lake in which there is no annual mixing of the waters from the top and bottom of the lake. This lake in particular is known for its bizarre chemistry which include build up of very high concentrations of sulphurated hydrogen. Such lakes have a high potential for evidence of ancient plant and animal life.