Elysium, otherwise known as the Elysian Fields or Elysian Plains, is a conception of the afterlife that developed over time and was maintained by some Greek religious and philosophical sects and cults. It was initially separated from the Greek underworld – the realm of Hades. Only mortals related to the gods and other heroes could be admitted past the river Styx. Later, the conception of who could enter was expanded to include those chosen by the gods, the righteous, and the heroic. They would remain at the Elysian Fields after death, to live a blessed and happy afterlife, and indulge in whatever they had enjoyed in life.