Hafit period tombs and remains have also been located across the UAE and Oman in sites such as Bidaa bint Saud, Jebel Al-Buhais and Buraimi. The first find of Hafit era tombs is attributed to the Danish archaeologist PV Glob in 1959, and the first of many excavations of these took place a few years later. Located in the area south of the city of Al Ain, the Jebel Hafeet Desert Park contains the original necropolis of Hafit Graves which led to the naming of this period in human history in the emirates. A series of ridges leading from the main part of Jebel Hafit toward Al Ain each contain groups of Hafit tombs. Finds at Jebel Hafit include the remains of some 317 circular stone tombs and settlements from the Hafit period, as well as wells and partially underground Falaj irrigation systems, as well as mud brick constructions intended for a range of defensive, domestic and economic purposes. The Al Ain Oasis, in particular, provides evidence of construction and water management enabling the early development of agriculture for five millennia, up until the present day. Pottery finds at Hafit period sites demonstrate trading links to Mesopotamia, contiguous to the Jemdat Nasr period (3100 – 2900 BC). Evidence of trading links with Mesopotamia are also found in the subsequent Umm Al Nar and Wadi Suq periods of UAE history.