One of the most remarkable examples of Nabataean engineering in Petra is the Arched Cistern of Jebel Haroun. Located at the base of the mountain's summit, this cistern measures approximately 18.0 x 5.0 meters and remains functional today. Partially hewn into the bedrock, it features masonry walls and is supported by fifteen arches built in the distinctive Nabataean style. Originally constructed to serve the local residents, the cistern ingeniously incorporates channels that direct rainwater from the mountain summit into the reservoir. Over time, it has also played a crucial role in providing water to visitors of the shrine of Prophet Aaron.

From 1997 to 2008, the Jordanian Department of Antiquities undertook significant restoration work on the cistern. This included restoring and reconstructing the external facade of the western wall, repairing and rebuilding the staircase leading to the cistern's roof, which serves visitors heading to the tomb of Prophet Aaron. Additionally, maintenance efforts addressed structural issues with the roof to prevent collapse and ensure visitor safety. The interior was cleaned of accumulated dirt and debris, and both the arches and inner walls were reinforced.