As Pluto gained importance as an embodiment of agricultural wealth within the Eleusinian Mysteries, from the 5th century BC onward the name Hades was increasingly reserved for the underworld as a place. Neither Hades nor Pluto was one of the traditional Twelve Olympians, and Hades seems to have received limited cult, perhaps only at Elis, where the temple was opened once a year. During the time of Plato, the Athenians periodically honored the god called "Plouton" with the "strewing of a couch" "(tên klinên strôsai)". At Eleusis, "Plouton" had his own priestess. Pluto was worshipped with Persephone as a divine couple at Knidos, Ephesos, Mytilene, and Sparta as well as at Eleusis, where they were known simply as God "()" and Goddess "(Thea)".