Ordinary Pebble (Lighthouse)

This Ordinary Pebble is found at on a rock at the entrance to a cave on the northern side of Western Watch in Drustvar. It is part of the Riddle of Baa'l. Zoom all the way in - the pebble is on top of one of the larger rocks, covered up by the brush.

Solution
... Next pebble is found in cave in Tiragarde Sound