Plymouth is a city of 243,795 inhabitants (2001 census) in the southwest of England, or alternatively the Westcountry, and is situated within the traditional county of Devon. It is located at the mouths of the rivers Plym and Tamar and at the head of one of the world's largest and most spectacular natural harbours, the Plymouth Sound. The city has a rich maritime past and was once one of the two most important Royal Navy bases in the United Kingdom, a factor that made the city a prime target of the Luftwaffe during the Second World War.