Thrall Caverns

The thrall caverns made up the upper level of the mind flayer city of Oryndoll.

Description
In construction, they resembled troglodyte warrens and most of the district was home to lizardfolk, tren, and troglodyte thralls. The largest cavern hosted a deep freshwater lake that was kept stocked with blind cavefish. Other smaller pools were dotted around the district, and were typically where other reptilians lived. The smaller caverns were occupied by duergar and other thralls under the control of the illithid. This section of Oryndoll was often what adventurers ran across in their travels, leaving them unaware of the bustling den of horrors that lay beneath it.

The thrall caverns were where most routes into Oryndoll reached, as there were hundreds of tunnels that connected it to the rest of the underdark. The caverns were connected to Oryndoll proper through multiple heavily fortified staircases that traveled down to the ring caverns. These staircases stretched down between 100 and 150 feet (30 and 46 meters) and had fortifications every 30 feet (9 meters).

Locations in the Thrall Caverns

 * The Flowstone Tapestry: This was a natural rock formation of sparkling calcite.
 * The Void Pool: This was a seemingly unremarkable pool of water in the northeastern Thrall Caverns.