Physical Features
The UK constitutes the greater part of the British Isles. The largest of the islands is Great Britain, which comprises England, Scotland and Wales.

The next largest is Ireland, comprising Northern Ireland, which is part of the UK, and the Irish Republic. Western Scotland is fringed by the large island chains known as the Inner and Outer Hebrides, and to the north of the Scottish mainland are the Orkney and Shetland Islands.

With an area of about 243,000 square kilometers (93,000 square miles), excluding inland water, the UK is just under 1,000 kilometers (about 600 miles) from the south coast to the extreme north of the Scottish mainland and just under 500 kilometers (around 300 miles) across at the widest point.

Key Features

• Highest mountain: Ben Nevis, in the Highlands of Scotland, 1,343 m (4,406 ft)
• Longest river: the Severn, 322 km (200 miles) long, which rises in central Wales and flows through Shrewsbury, Worcester and Gloucester in England to the Bristol Channel
• Largest lake: Lough Neagh, Northern Ireland, 396 sq km (153 sq miles)
• Deepest lake: Loch Morar in the Highlands of Scotland, 310 m (1,017 ft) deep
• Highest waterfall: Eas a'Chual Aluinn, from Glas Bheinn, also in the Highlands of Scotland, with a drop of 200 m (660 ft)
• Deepest cave: Ogof Ffynnon Ddu, Powys, Wales, 308 m (1,010 ft) deep
• Most northerly point on the British mainland: Dunnet Head, north-east Scotland
• Most southerly point on the British mainland: Lizard Point, Cornwall
• Most easterly town in England: Lowestoft, Suffolk
• The Channel Tunnel, near Dover in Kent, links England and France. It is 48 km (30 miles) long, of which nearly 37 km (23 miles) are actually under the English Channel.
  

Find out more from these websites:

Met Office - the UK's national weather service

National Statistics - natural environment

UK 2005: The Official Yearbook of the UK - offers color maps and further geographical information.