Literally “Lake of Mustard”, Tam Dil is situated near Saitual Village, about 110 kms from Aizawl. Having been developed as an important pisciculture centre by the Fisheries Department and a holiday resort by the Tourism Department, this is one of the most frequented lakes in the state. The lake and the surrounding thick forest are home to wide species of trees, plants and animals.

According to folklore, a couple used to have a jhum cultivation in this small valley surrounded by hills, but the man died suddenly and left the woman to look after the crops alone. In the middle of the field, there was a mustard plant that was bigger than the others and one night the widow was told in her dreams by her dead husband to take special care of the mustard plant which would bring her great blessings. She did as she was told, and the plant thrived very well and grew bigger and bigger. After sometime, the widow remarried but her new husband did not like her to keep anything that would remind her of her former husband and so he pulled the plant up by roots and threw it away. Out of the hole thus left in the ground water flowed out immediately and filled the valley to become a large and beautiful lake.