Duhuls were small fissures in the ground that led to natural pools of water. Most of these fissures were located along the hillsides of the Pit of the Ghuls near the western tip of the Mountains of Forgotten Dreams, in the High Desert of Zakhara.
Water was always scarce within the High Desert, so local nomads fiercely guarded duhuls that they claimed. A nomad claimed a duhul by etching his personal mark into the stone entrance. These nomads could usually be persuaded to allow others to use their duhul if given a gift or half of whatever amount of water was extracted.
Duhuls could range as far as 200 feet (60 meters) before leading to water and were no larger that 4 feet (1.2 meters) in diameter. Travelers braving the tunnels often had to deal with bites from ants or beetles, and nasty scrapes from the sharp rock surfaces.