Also referred to as Sad al-Kharruba, which means ‘carob dam’ in Arabic, this is a remarkable example of a small Nabataean dam.  It is located across a gorge in a high sandstone outcrop and the dam masonry wall originally had three courses, which are now missing (as indicated by cuts in the rock for anchoring the rows). The dam is named after a big carob tree ('kharruba' in Arabic) that grew inside it. The Nabataeans utilized it for agriculture purposes in the Bayda area, and the Romans and Byzantines may have used it similarly later on. Due to Petra’s location at the crossroads of three zoogeographic zones, the area has a wide variety of landscapes and climatic conditions that have resulted in diverse flora and fauna.  Decades ago this area was covered with four predominant indigenous tree species: Kermes oak, Phoenician juniper, Mt. Atlas pistachio and carob. Unfortunately, three of these species are now on the world list of endangered species.  Petra is also home to many other rare species, such as the Petra Iris, Romulea of Petra and the blue lizard of Petra.