Pocket Guide to the Empire, Third Edition: Atmora

Aldmeris
Virtually nothing is known of the elven homeland. Its location, its environment, its politics, its religion, even its current existence are the stuff of conjecture. Translation from the ancient tapestries and texts in the Crystal Tower of Summerset have yielded only the barest of sketches of a beautiful but very strange land. In no representation of Aldmeris are there any trees or life but the Aldmer themselves. It appears always as an endless city, built upon itself over and over again, until no nature remains at all. The highest towers are reserved for interring the dead, a tradition continued on the Crystal Tower itself.

What had happened in Aldmeris since the elves who settled in Tamriel left is perhaps the oldest of all mysteries. For countless centuries, adventurers have sought "Lost Aldmeris," only to return disappointed, if they return at all. Some say that Aldmeris was sunk into the sea by the angry gods of the Aldmer. Others claim that the elven homeland has left Mundus, and will only return when the races of mer are united as one.

Source: The Imperial Libary