The Dry Land is where the people of the archipelago and reaches of Earthsea go when they die. It is a realm of shadow and dust, of eternal night where the stars are fixed in the sky and nothing changes. The souls who live there have an empty, dreary existence, and even "lovers pass each other in silence". Wizards can, at great peril, cross from the land of the living to the Dry Land and back again by using their magic to step over the low stone wall that separates the two realms. At the bottom of the valley of the dead lie the cities of the dead. Beyond that lie the Mountains of Pain where a dry river bed leads down.
Ursula Le Guin has stated that the idea of the Dry Land came from the "Greco-Roman idea of Hades' realm, from certain images in Dante Alighieri's work, and from one of Rainer Maria Rilke's Elegies."
A Wizard of Earthsea
Ged accidentally goes too far into the Dry Land attempting to bring back Pechvarry's son Ioeth back. His return to the living world is stopped by his Shadow. He only survives because of the actions of the local witch and his otak.
The Farthest Shore
In The Farthest Shore, the wizard Cob breaks the barrier between life and death at the source of a river bed in the Mountains of Pain in his attempt at immortality. Ged loses his magical powers in the Dry Land closing it. No longer able to cross the wall, he and his companion King Lebannen become the first to traverse the Mountains of Pain to return to life.