Banasura Sagar Dam, Earth dam in Wayanad, India

Banasura Sagar Dam is a homogeneous rolled earth-fill dam in Padinjarathara, Wayanad district, Kerala, impounding the Karamanathodu tributary of the Kabini River. It stands 38.5 metres high and 685 metres long, built from large rocks, stones and soil between the Banasura hills. In the photograph the bare reddish-brown soil crest runs low across the water, with a row of thin dark posts on its right side.

Construction began in 1979 as part of the Banasurasagar Project to relieve water scarcity and supply the Kakkayam hydroelectric power station. The finished structure became the largest earth dam in India.

The name recalls Banasura, the mythical demon king and son of Mahabali, said to have performed penance in the nearby hills. The surrounding mountains also carry his name, linking the landscape to this ancient story.

Reaching the site from Calicut International Airport, 90 kilometers (56 miles) away, involves traveling through Kalpetta, located 21 kilometers (13 miles) from the structure. The approach follows winding hill roads lined with tea estates and forest on both sides.

The solar panels sit on floats on the reservoir surface rather than on land, which is why the sources call it India's first solar installation atop a dam. The dam itself is an earth-fill structure of stone, boulders and soil, 685 m long and 38.5 m high, completed in 2004.