Buried Realms

The Buried Realms was a domain of the Underdark lying underneath the vast desert of Anauroch. The area was called the Phaerlin by the phaerimm who dwelled there, though this name was little-known on the surface.

Geography
The whole of the Buried Realms was bordered by the Sharnwall. This magical artifice was created in ancient times by the sharn to imprison the phaerimm. It functioned as a barrier, confining the phaerimm to the Buried Realms. They could not travel between their realm and the rest of Faerûn by any skill or magic they were capable of. However, all other creatures could cross it freely.

Many of the deepest catacombs of Oreme, former capital of the fallen sarrukh empire of Isstosseffifil, directly connected to this region. However, a barrier similar to the Sharn Wall that was constructed by the ruin's lich rulers prevented any phaerimm from entering the city.

As Anauroch was once the site of the old Netherese Empire and its successor states, many Netherese ruins could still be found in the Buried Realms. However, the threat of the phaerimm discouraged most adventurers from delving into the Buried Realms, even though they could pass the Sharnwall, so the sites and settlements in the area remained largely unknown to surface dwellers by the 14 century DR.

History
In -33,800 the phaerimm inhabitants were forced to flee deeper into the Underdark as the Isstosseffifil empire attempted to drown them by rerouting the Narrow Sea.

On Nightal 20, the, the magical barrier was breached near the city of Evereska, unleashing the phaerimm to cause chaos in the lands outside. Eventually, the return of Thultanthar and the forces combating the phaerimm kept them at bay.

Inhabitants
This area was largely home to the terrible phaerimm. It was also inhabited by the asabi descendants of the Isstosseffifil empire, who were often controlled either directly or secretly by the phaerimm.