Geography of Dorset is the Blackmore Vale, a relatively low-lying area of clays and limestones of Jurassic age. The south-east of the county forms part of the Hampshire Basin, an asymmetric syncline covered in sands and gravels of Paleogene age. The main rivers in the county are the Stour, Frome and Piddle. The Stour is the county's largest river, although its source is in the neighbouring county of Wiltshire. The Frome and Piddle both lie wholly within the county. The whole of Dorset's coastline is designated part of the Jurassic Coast World Heritage Site, and contains examples of many different coastal landforms, reflecting
Dorset and East Devon (European Parliament constituency) and West Dorset. The constituency replaced parts of Devon, Somerset and West Dorset and Dorset East and Hampshire West. It became part of the much larger South West England constituency in 1999. ! style="background-color: " | Dorset and East Devon (European Parliament constituency) Dorset and East Devon was a European Parliament constituency covering all of Dorset in England, with the exception of Christchurch, plus parts of eastern Devon. Prior to its uniform adoption of proportional representation in 1999, the United Kingdom used first-past-the-post for the European elections in England, Scotland and Wales. The European Parliament constituencies used under that system