Banasura Sagar Dam

Banasura Sagar is the largest earth dam in India and the second largest of its kind in Asia. Built in 1979 across the Karamanathodu, a tributary of the Kabini, it is made of stones and boulders rather than concrete. The dam supports the Kakkayam hydroelectric project and supplies water for drinking and irrigation, which matters most in the dry summer months.

It sits at the foot of the Banasura hills near Kalpetta. Small islands rise out of the reservoir, and in the monsoon the water climbs high enough to cut off low hills and turn them into new islands for a while.

The name comes from Banasura, son of King Mahabali, whose return is celebrated at Onam. Local legend says Banasura did penance on the hills that now carry his name.