South West England development because of its environmental importance, which contributes to the region's attractiveness to tourists and residents. Geologically the region is divided into the largely igneous and metamorphic west and sedimentary east, the dividing line slightly to the west of the River Exe. Cornwall and West Devon's landscape is of rocky coastline and high moorland, notably at Bodmin Moor and Dartmoor. These are due to the granite and slate that underlie the area. The highest point of the region is High Willhays, at , on Dartmoor. In North Devon the slates of the west and limestones of the east meet at
County of London Government Act 1963 replaced the county with the much larger Greater London administrative area. The county occupied an area of just under and lay within the London Basin. It was divided into two parts (north and south) by the River Thames, which was the most significant geographic feature. It was bordered by Essex to the north-east, Kent to the south-east, Surrey the south-west and Middlesex to the north. The highest point was Hampstead Heath in the north of the county at , which is one of the highest points in London. In 1900 a number of boundary anomalies were abolished.