The geography of Cornwall describes the extreme southwestern peninsula of England west of the River Tamar. The population of Cornwall is greater in the less extensive west of the county than the east due to Bodmin Moor's location; however the larger part of the population live in rural areas. It is the only county in England bordered by only one other county, Devon, and is the 9th largest county by area, encompassing 3,563 km² (1,376 mi²). The length of the coast is large in proportion to the area of the county. Cornwall is exposed to the full force of the prevailing south-westerly winds that blow in from the Atlantic Ocean.