Is located to the east and directly opposite the veranda of the old Newnes Hotel and the summit is 340m above the Wolgan River. The mountain is part of what is called (see) Island Mountain. Allan Watson of the Newnes Hotel explains," When you sit on the veranda and ask, I wonder what it is like up there?" Since there is no intention of actually going to find out, the answer is a mystery." Allan is not sure how the name came about, but it was so called prior to the 1950s. Ref: Interview with Dick Bird, 29th January 2010, who recalls his father Jim called it Mystery Mountain, because in the 1940s, three sovereigns were found at the base of the mountain. A third suggestion comes from Thomas Ebersoll, proprietor of the Newnes Holiday Cottages, who says the name is a corruption of Misty Mountain, because for many months of the year in the early mornings the mountain is shrouded in mist. A fourth explanation comes from a previous resident of the valley who also recalled Jim Bird telling him that a group of people went up the mountain but one of the group never came back. Ref: Oral history Bruce Tweedie, 2nd May 2016.