Dolmen

A  Dolmen is an item used during While Guthix Sleeps. When mixing the corresponding potion's ingredients on a statue in the Ancient Guthix Temple, you will receive one of the eight dolmens. When placing a dolmen on the stone table in the temple, a large dolmen will rise from the huge stone circle in the middle of the room. After all eight dolmens are placed on the table, the stone circle will raise up and unlock the door to the Stone of Jas. Oddly, the Dolmens on stone circle disappear afterwards.
 * There is a Dolmen below the Tree Gnome Village. It has not been found of use at the moment.
 * These (left) dolmens seem to represent the ones from that of the stone circle south of Varrock.

Trivia

 * The stone circle seems to have similarities to the ancient site known as Stonehenge.
 * A dolmen is also a small table used by gnomes (in-game).