In a unique campaign to save Ajmer's 900-year-old Ana Sagar lake, children and citizens of the city joined hands. The lake is so polluted now that fish don't survive in its waters. Once a famous wetland and stop over for migratory birds, the three-km lake in Ajmer is faced with extinction as human effluents and encroachments are slowly killing off the lake which has shrunk to half its size in just seven years.