The three Hesperides were sisters who guarded the Garden of the Hesperides, aptly named. They were the daughters of Atlas.
The garden was a gift of Mother Earth to Hera on her wedding day. In this garden, which only immortals could reach, were the Golden Apples. One of Hercules' twelve labors was to retrieve these apples, but, being mortal, he could not. He convinced Atlas to do so for him.