The Oak of Mamre near Hebron is where Abraham pitched his tent and saw the angels.

The Oak of Mamre near Hebron is where Abraham pitched his tent and saw the angels. 
"Then one who had escaped came and told Abram the Hebrew, for he dwelt by the terebinth trees of Mamre the Amorite, ....." (Gen. 14:13)
"Then the LORD appeared to him by the terebinth trees of Mamre, as he was sitting in the tent door in the heat of the day. So he lifted his eyes and looked, and behold, three men were standing by him; and when he saw them, he ran from the tent door to meet them, ....." (Gen. 18:1- 2)

 There is a tradition that the Oak of Abraham will die before the appearance of the Antichrist. The main oak trunk has appeared to be dead since 1996. Following construction work in the 1970s, a wooden ring in the form of a chalice was built around the tree, and its roots began to die. In 1997, a small sprig was seen growing near the withered oak. In October 2016, Russian botanists began a project to save the tree. In 1998 a root sprout appeared. (wiki)