At 515 m, Ryder's Hill is one of the highest points on the southern part of Dartmoor

Dartmoor

Dartmoor is an area of moorland in south Devon, England. Protected by National Park status, it covers .The granite upland dates from the Carboniferous period of geological history. The moorland is capped with many exposed granite hilltops known as tors, providing habitats for Dartmoor wildlife. The...

, Devon

Devon

Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...

, England. On its summit there are two standing stone

Standing stone

Standing stones, orthostats, liths, or more commonly megaliths are solitary stones set vertically in the ground and come in many different varieties....

s and a low cairn

Cairn

Cairn is a term used mainly in the English-speaking world for a man-made pile of stones. It comes from the or . Cairns are found all over the world in uplands, on moorland, on mountaintops, near waterways and on sea cliffs, and also in barren desert and tundra areas...

, on top of which is a triangulation pillar.

One of the standing stones is called Petre's Bound Stone and it marks the boundary of three civil parish

Civil parish

In England, a civil parish is a territorial designation and, where they are found, the lowest tier of local government below districts and counties...

es: Dartmoor Forest

Dartmoor Forest

Dartmoor Forest is a civil parish in Devon, England. It was formed in 1987 by the splitting of the former parish of Lydford. It covers about entirely within Dartmoor National Park, and is the largest parish in Devon. Despite its size its population in 2001 was only 1,619....

, Holne

Holne

Holne is a village and civil parish on the southeastern slopes of Dartmoor in Devon, England. A community has existed here since at least the 11th century, and today a population of around 250 people is served by a church and a public house, the Church House Inn.-Village:The Church of St Mary the...

 and Buckfastleigh

Buckfastleigh

Buckfastleigh is a small market town and civil parish in Devon, England situated beside the Devon Expressway at the edge of the Dartmoor National Park. It is part of Teignbridge District and, for ecclesiastical purposes lies within the Totnes Deanery. It has a population of 3,661...

. The cairn, which is not very prominent, has an important history. It was one of the boundary markers of the Forest of Dartmoor

Forest of Dartmoor

The Forest of Dartmoor is an ancient royal forest covering part of Dartmoor, Devon, England.A royal forest was an area reserved by the king for hunting, and William the Conqueror introduced the concept of forest law in England in the 11th century...

 mentioned in the Perambulation of 1240 and has been known as "Knattleborough" (or variations of that name) since at least the 17th century.

Ryder's Hill can be reached by walking up Holne Ridge from Combestone Tor, past Horn's Cross, a distance of about 3 km. From the summit there are good views over southern Dartmoor.