"Talvan" most commonly refers to the sacred forest in Vrajamandal, India, where Balarama killed the demon Dhenukasura. It is a pilgrimage site with a temple dedicated to Balarama and his consort Revati, next to a lake called Sankarsana-Kunda. The name "Talvan" comes from the palm trees that used to fill the forest.
https://harekrishnainfo.blogspot.com/search/label/RevatiSankarshana
