Ein es-Sultan is a natural spring in Jericho, at the site of ancient Jericho, which has been identified with the tell (archaeological mound) known as Tell es-Sultan.
It is known by Jews and Christians as the Spring of Elisha/Elisha's Spring, based on a biblical story about Prophet Elisha (see 2 Kings 2: The early acts of Elisha: bringing life and death (2:19-25)). In the Middle Ages, it was also known as Elisha's Fountain.[1]
The Ein as-Sultan camp just north of it is named for the spring.