High Willhays is near the northwestern edge of Dartmoor, about south east of
Meldon Reservoir and about south of the town of
Okehampton. Although it is the highest point of the moor, it is relatively insignificant in comparison to most of the moor's
tors, consisting of no more than a few low outcrops of rock along a north–south ridge. The largest outcrop is crowned with a cairn. The more impressive, but slightly lower,
Yes Tor is about north along this ridge, which is known as "the roof of Devon".{{cite book High Willhays and Yes Tor are the only summits in England south of
Kinder Scout in the
Peak District to rise above , apart from
Black Mountain on the Welsh border. Before
Ordnance Survey measured accurately the heights of High Willhays and Yes Tor many people believed Yes Tor was the higher of the two, and it was only the local farmers and moormen that believed the contrary. However, the first topographical survey of the area carried out by Ordnance Survey suggested that High Willhays was higher, although the difference has now been measured at just . William Crossing stated that High Willhays was the highest point in England south of
Ingleborough in the Yorkshire Dales, but since then surveys have shown that Kinder Scout is also higher (albeit less
prominent). The geology of High Willhays, like most of Dartmoor, consists of
granite intruded about 280 million years ago. However High Willhays is in an area of the northern plateau of the moor where the exposed rock has noticeably fewer of the large
feldspar megacrysts that are typical of most of Dartmoor's
tors.{{cite book High Willhays is within one of Dartmoor's
Danger Zones, areas used periodically by the
British Army for exercises. Red flags are raised around the perimeter when live-firing is due to take place. , showing High Willhays at the centre ==References==