The Battle of Grand Gulf was fought on April 29, 1863, during th: England accounts for 53 per cent of the UK, covering 50,350 square miles (130,395 km2).[150] Most of the country consists of lowland terrain,[151] with upland and mountainous terrain northwest of the Tees–Exe line which roughly divides the UK into lowland and upland areas. Lowland areas include Cornwall, the New Forest, the South Downs and the Norfolk Broads. Upland areas include the Lake District, the Pennines, the Yorkshire Dales, Exmoor, and Dartmoor. The main rivers and estuaries are the Thames, Severn, and the Humber. England's highest mountain is Scafell Pike, at 978 metres (3,209 ft) in the Lake District; its largest island is the Isle of Wight.