Sschindylryn's Gate

Sschindylryn's Gate was a Toril-Oerth portal leading to Erelhei-Cinlu in Greyhawk's Underdark.

History
The portal was discovered by scouts from the city of Sschindylryn, a drow city under Cormyr known for its use of portals to explore and conquer other parts of the Underdark. During a battle with Menzoberranzan, the portal was damaged and none from the western city knew how to operate it or to where it lead.