Age of Worms
The Nyr Dyv, "Lake of Unknown Depths,” is centrally located in the Flanaess. It is the largest known body of fresh water known to the people of that region.
Geographically, the Nyr Dyv is located north of the Free City of Greyhawk, which can easily be reached from the lake via the Selintan River. As such, Rhennee barges may be found navigating on the lake, along with commercial or naval traffic bound to or from the Free City.
The city of Dyvers, the Cairn Hills, and the Duchy of Urnst also border the southern shores of the Nyr Dyv. To the west lies the Kingdom of Furyondy, to the east the County of Urnst, and to the north the Shield Lands and the Empire of Iuz.
As its nickname suggests, the true depth of the lake is unknown, but certainly significant. Its waters support a variety of aquatic life, some of it quite dangerous. Piracy is also a concern, though the waters are patrolled by ships from Dyvers, Furyondy, Greyhawk, and the Urnst states.
The Nyr Dyv has three major navigable inlets: the Velverdyva to the west, and the Veng and Artonsamay to the north. Its two major navigable outlets include the Selintan to the south and Nesser to the southeast. Major ports on or near the Nyr Dyv include Dyvers, Greyhawk, Nyrstran, Leukish, High Mardreth, Radigast City, Alhaster, Admundfort,Critwall, and Willip.
The Nyr Dyv is rumored to hold the remains of an ancient civilization known as the Isles of Woe, which sank beneath the waves prior to the Great Migrations. Many explorers have fruitlessly searched the lake for evidence of this civilization. Though unusual pieces of jewelry, strange silver coins, and alien carvings of obsidian reputed to be remnants of the Isles of Woe are sometimes found in the markets of surrounding cities, most are regarded as forgeries.