Ancient India has been rich not culturally alone, even technologically too. The Oldest Dam in the World that is still in use today is THE GRAND ANICUT and this dam is from kallanai, Tamil Nadu. It is located on the Cauvery River, 24 km from Tiruchirapalli, Tamil Nadu. This masonry dam was built in the 2nd Century by Chola King Karikalan and is 1,082 feet long with a maximum height of 18 feet and is 40-60 feet wide. It was remodeled and fitted with sluice gates in 1899-1902. For nearly two millennia it has irrigated millions of acres of land.