ThePinnacles are twochalk formations, including astack and a stump, located near Handfast Point, on theIsle of Purbeck inDorset, southernEngland.
The Pinnacles lie directly east ofStudland, approximately 200 metres south ofOld Harry Rocks and about 4 kilometres northeast ofSwanage. The chalkheadlands of theBallard Downs are owned by theNational Trust. The rocks can be viewed from the Dorset section of theSouth West Coastal Path.
The downlands of Ballard Down are formed of chalk with some bands offlint, and were formed approximately 66 million years ago. The bands of stone have been gradually eroded over the centuries, some of the earlier stacks having fallen while new ones have been formed by the breaching of narrow isthmuses.[1] Across the water to the east the Needles on the Isle of Wight are usually visible. These are also part of the same chalk band and only a few thousand years ago were connected to Ballard Down.
To form the stacks, the sea gradually eroded along the joints and bedding planes where the softer chalk meets harder bedrock of the rock formations to create a cave. This eventuallyeroded right through to create an arch. The arch subsequently collapsed to leave the stacks called The Pinnacles.
50°38′14″N1°55′38″W / 50.6373°N 1.9271°W /50.6373; -1.9271