At 80,823 square miles, Great Britain is the world’s ninth largest island, made up of England, Scotland, and Wales. Just behind it is Ellesmerein in the Canadian Arctic Archipelago. Covering almost 76,000 square miles, the island is located off of Greenland’s northwest coast.

England is home to 10 of the U.K.’s 15 national parks, including Lake District National Park. Before it was protected land, the poet William Wordsworth wrote “A Guide through the District of the Lakes.” The work goes beyond a standard guidebook to describe the region where Wordsworth was born in poetic verse. Modern hikers can still follow the paths described in Wordsworth’s early 19-century guide.

London is far and away the U.K.’s largest city, with a population of nearly 9 million people. In second place, you’ll find Birmingham, located in England’s west Midlands with nearly 3 million residents. The largest U.K. city not located in England is Scotland’s Glasgow, which has a population of 2.11 million people.

The United Kingdom might be known more for its rolling hills, but hikers can still find some elevation. At 4,412 feet high, Ben Nevis is the U.K.’s tallest mountain, located in the Scottish Highlands. Over 100,000 visitors attempt the summit each year. The climb typically takes between seven to nine hours.

The prime meridian, the imaginary north-south line dividing the Eastern and Western Hemispheres, runs through London’s Greenwich Observatory. The longitudinal location of any other place on Earth is measured in terms of its east-west distance from this line, which is also the reference point for Greenwich Mean Time.

Cardiff, the capital of Wales, has a population of about 400,000 — roughly the same population as U.S. cities like Sacramento or Oakland, California. In the center of the city is Cardiff Castle, and while it looks like a medieval fortress, it was actually built in the 19th century. Cardiff is the largest of Wales’ six cities; the second largest, Swansea, has a population of 239,000.

Differences abound between the Scottish Lowlands and Highlands, and one primary distinction is the capital. Edinburgh, the second-largest city in Scotland, is the capital of the lowlands. Inverness, a northeastern coastal town near the famous Loch Ness, is the highlands’ capital. The city and its surrounding suburbs are home to about 75,000 people.

Scotland’s Shetland Islands are located about 400 miles from the Arctic Circle. The northernmost point in the U.K. is the island of Oosta (or Out Stack). Located about 130 miles north of the Scottish mainland, the archipelago consists of about 100 islands, 20 of which are inhabited.

Loch Ness might be the most famous, but it’s not Scotland’s only lake (or “loch” in Scottish Gaelic). There are more than 30,000 lakes in Scotland, including Loch Lomond, the country’s largest lake, which has a 27.4-square-mile surface area. It’s located in southern Scotland, roughly a one-hour drive from Glasgow.

While Northern Ireland is part of the United Kingdom, Great Britain is the name for the island which is made up of Scotland, England, and Wales. Northern Ireland is located on the island of Ireland, which it shares with the Republic of Ireland. Northern Ireland does participate with Great Britain’s Olympic team, though, which goes by the name “Great Britain and Northern Ireland Olympic Team.”