Rama, Sita, and Lakshmana heard music in the forest. Following the music, they came to a lake.
"I don't understand," said Rama. "Where are the musicians?"
A wandering rishi explained. "The rishi Mandakarni once lived here, and he practiced austerities for a thousand years. The devas feared him, so they sent five apsaras to seduce and distract him. The plan worked: Mandakarni was besotted. He built a house for the apsaras, and then he hid the house beneath this lake. You can hear them even now, as they sing and dance and make merry in the depths of Five-Apsaras Lake."