Mary Tavy is located on the western side of the Dartmoor National Park and is in the West Devon Local Authority area. It is an old mining village named after the 13th Century church of St. Mary’s and the River Tavy. Mary Tavy lies approximately 4 miles north east from Tavistock, 18 miles to Plymouth; two miles away is Brentor’s landmark church on a peak. Mary Tavy nestles on the eastern side of the Cholwell valley leading to the River Tavy. The Parish of Mary Tavy is predominately made up of Blackdown and the old village of Mary Tavy but now includes the hamlets of Horndon, Zoar and Grendon. It is a scattered village that contains open moorland within its boundaries, and approaching south along the A386 you pass Gibbet Hill and the remains of Wheal Betsy in the moorland valley.
The A386 continues through the middle of Mary Tavy and adjacent to the road is the village recreation field and the village hall, The Coronation Hall. To the west of the A386 lies the area called Blackdown. This area is now mainly residential, but has evidence of the old railway line which runs adjacent to the River Burn. To the east of the A386, turning left at the War Memorial down Bal Lane lie the remains of Wheal Friendship. Continuing down Bal Lane just past the Horndon turning is the Village School. This area is known as old Mary Tavy – rather than Blackdown and it contains one of the village’s thatched cottages. Further west adjacent to Cholwell Brook is the village’s 13th century Parish Church, Mary St. Tavy. Past the Church at the end of the lane is the Hydro Electric Power Station, which is powered by water taken from the River Tavy and the old mine leat. This lane used to be the thoroughfare between Mary Tavy and its neighbouring village Peter Tavy but is now a bridle path which runs adjacent to the River Tavy