The shrine marks a place where Roman legend claims the divine twins Castor and Pollux stopped to water their horses while passing through the city, and where they announced Roman victory at the Battle of Lake Regillus, 495 BCE. During the Roman Empire, when another spring in the city had dried up, the Vestal Virgins used this spring to supply water for their religious ceremonies. The water at the Lacus Iuturnae was thought to have healing properties. The elderly and infirm would go to the spring with offerings in order to secure the assistance of Juturna in curing their malady.