Deeping Steppes as named by Dargain the Gnomish adventurer who happened upon this place when attempting to find lost friends in a nearby series of caves and was swept in by the unexpected surge of an underground river, perhaps due to shifting of plates or erosion of a natural barrier. The cavern was sealed and unknown until being discovered by Dargain.
This is a region of the underdark where a series of very large plateaus occupy a huge underground cavern. The cavern is situated near a very common and sometimes treacherous underdark route know as The Underway (in my version of the world) which reaches from the Dales to Silverymoon regions in the Forgotten Realms.
In an area albinos are considered to be evil mystics and locals ward themselves against them by turning their backs to them to avoid being mesmerized. Suddenly the angeliclly pale loner with white hair and violet hued-eyes is suddenly an outcast, and his companions are treated as if they have been mystically bonded into his service, and could be treated with attempts to intervene or given the same stony treatment. Expect poor quarters, no hospitality and to pay twice as much for everything.