Scotland - The Northwest Highlands, the Cairngorm Mountains, the Grampian Mountains and the Southern Uplands. Ben Nevis is the UK's highest peak and is found in the Grampian Mountains.
England - The Pennines, Lake District, Dartmoor and Exmoor. Scafell Pike is the highest mountain in England and is found in the Lake District.
Wales - Snowdonia and the Brecon Beacons. Snowdon is the highest mountain in Wales and is found in Snowdonia.
Lowland areas of the UK include:
the Fens in East Anglia - the lowest place in the UK