The Pit of Graz'zt is a hole, a hundred yards wide, on a plateau overlooking the Imrabêl valley. It descends down to Underdark sector Berolaz. It has a wide path, not maintained since the God Era, that spirals all the way to the bottom. In some areas this dug into the wall, forming a protective walk area from the elements, while in other areas it is in the open, with nothing to keep one from slipping over the edge.
In the Demon Spawn War, this pit was carved out on order of Graz'zt. The normal routes his forces used to reach the surface from Barhaz Halarax took too long; indirect routes. Graz'zt put a great labor force to work digging straight up to the surface. They dug a wide path that six human-sized soldiers could walk abreast and did this over two miles. After this was done, they turned to boring out the center of the dig site. After three decades, they had created an unnatural hole rising from the darkness of Berolaz to the surface sector Marninnoth. All the rock and debris from this dig were taken back through the Barhaz Halarax where they ended up as embankments leading the rift's exit on Azzagrat.