Foggintor Quarry and King's Tor are two sites on the high ground towards the west side of Dartmoor National Park, near Merrivale, viewable along a loop walk of 2.7 miles, partly off-trail. The former is an abandoned granite quarry, in operation from around 1830 to the early 20th century; it now consists of a cliff-lined basin centred on a large pool, with several ruined buildings close by. The latter is one of the innumerable granite summits on the moor, a low hill topped by photogenic piles of boulders, offering a 360 degree view over the surrounding moorland.
The walk is initially along the old access track, through the quarry itself, then west along a short section of the long-closed Princetown Railway, up to the tor, and finally cross-country over sometimes boggy terrain back to the start, which is a parking area along the B3357, 1.2 miles east of Merrivale.
The quarry is, or was, a popular place for primitive camping, on ledges overlooking the pool; an easy, 0.8 mile walk from the parking place. This location is quite scenic though does not have the varied plant life of some other old quarries on the moor such as Haytor.
From the parking area on the B3357, occupying an old sandpit, a track runs south towards Foggintor Quarry. It soon passes the ruins of the Red Cottages, a short line of one-room dwellings occupied by workers at the quarry, adjoining several small stone-lined fields. Just a few walls remain, plus two large yew trees. The track then passes by Yellowmeade Farm, still occupied, and continues to the ruins of Foggintor settlement, just north of the quarry; here are more wall fragments and foundations, from over a dozen separate buildings, all abandoned when the quarry closed. A little path leads to the actual quarry, entering from the north through a gap in the cliffs, running along the east side of the large pool then exiting to the south and rejoining the track. Stone from the quarry was used amongst other purposes to build Dartmoor Prison, just over one mile east, and also Nelson's Column in Trafalgar Square. The quarry is named for a tor that once existed on the site, removed by the excavations.
A short distance south of the quarry, the track intersects the old Princetown Railway, a single-track line in operation from 1883 to 1956, used mostly to take people and supplies to the prison. It largely followed the route of an earlier line, a branch of the Plymouth and Dartmoor railway, which was opened in 1814, transporting granite from Foggintor and other quarries. The track runs northwards to the vicinity of King's Tor, looping around three sides of the summit, which is reachable by a short path, or a cross-country walk. They rock outcrops on the tor extend 500 feet or more and are centred on the main group, rising about 15 feet above the surroundings. From the tor, one return route is north, back across the old railway and along a path that descends gradually, crosses a stream and rises to another car park (Four Winds), on the B3357; the start point is then 0.4 miles east. A slightly shorter route, cross-country all the way, is northeastwards, also crossing the railway and the stream, and later some boggy land, back to the Foggintor car park.