Mount Hor (Hebrew: הֹר הָהָר, Hor Ha-Har) is the name given in the Old Testament to two distinct mountains. One borders the land of Edom in the area south of the Dead Sea, and the other is by the Mediterranean Sea at the Northern border of the Land of Israel. The first Mount Hor is especially significant to the Israelites as Aaron the high priest, brother of Moses, died there.
Mount Hor in Edom (Mount Harun)
This Mount Hor is situated "in the edge of the land of Edom" (Numbers 20:23 and 33:37) and was the scene of Aaron's divestiture, death and burial. The exact location of Mount Hor has been the subject of debate, but based on the writing of Josephus it has customarily been identified with the Jebel Nebi Harun ("Mountain of the Prophet Aaron" in Arabic), a twin-peaked mountain 4780 feet above sea-level (6072 feet above the Dead Sea) in the Edomite Mountains on the east side of the Jordan-Arabah valley. On the summit is a shrine, the Tomb of Aaron, said to cover the grave of Aaron.
Some investigators at the turn of the 20th century dissented from this identification: for example, Henry Clay Trumbull preferred the Jebel Madara, a peak about 15 miles northwest of 'Ain Kadis (Kadesh Barnea), near the modern border between Israel and Egypt.
Northern Mount Hor
Another Mount Hor is mentioned in the Book of Numbers, defining the northern boundary of the Land of Israel. It is traditionally identified as the Nur or Amanus Mountains. When in the Second Temple period, Jewish authors seeking to establish with greater precision the geographical definition of the Promised Land, began to construe Mount Hor as a reference to the Amanus range of the Taurus Mountains, which marked the northern limit of the Syrian plain. Rabbinic writings also declare Amanah a boundary of the land of Israel, saying "from the mountains of Amanah, to the river of Egypt; whatever is within that line belongs to the land of Israel: but, whatever is without that line, is without the land."