Zoheleth stone, from I Kings 1 and 2 which is the place where Adonijah (one of King David's sons) and others, went to celebrate the usurping of his fathers throne as King of Israel. Story continues that in fact David was told of the plot by Bathseba and the prophet Nathan, and gave Solomon the crown just in time. I googled serpent stone, and snake rock, and Zoheleth stone, and found a number of really fun images, from which this and several other patterns emerged.

There are other translations for zoheleth (other than serpent), and this is that the zoheleth stone was a stone by slow moving waters, or perhaps a stone on which one could stand and use as a watch tower. Kings of Israel were appointed by rivers typically, so this is perhaps why Adonijah choose this spot. Thanks to a friend for this update on the meaning of zoheleth.