1. The Tower of London Located on the north bank of the River Thames, the Tower of London is a historic castle and palace in London. It has been a royal residence, a prison, a mint, a treasury, a zoo, and home to the Crown Jewels of the United Kingdom.

2. Buckingham Palace The official London residence and administrative headquarters of the British monarch. It is one of the largest and most iconic palaces in the world, and the Queen's Gallery is located within its walls.

3. Big Ben Although not a building itself, Big Ben is the nickname for the Great Bell of the clock at the north end of the Palace of Westminster, and is a symbol of London and the United Kingdom.

4. The Houses of Parliament Also known as the Palace of Westminster, this historic building houses the two houses of the Parliament of the United Kingdom: the House of Commons and the House of Lords.

5. The London Eye A giant Ferris wheel on the South Bank of the River Thames, offering panoramic views of the city. It is one of the most popular attractions in London.

6. St. Paul's Cathedral An Anglican cathedral in the City of London, designed by Sir Christopher Wren and rebuilt after the Great Fire of London. It is an example of Baroque architecture and is famous for its dome.

7. The British Museum Located in London, it is one of the world's oldest and largest museums, housing a vast collection of art and historical artifacts from around the globe.

8. The National Gallery An art museum in Trafalgar Square, London, housing a collection of over 2,300 paintings dating from the mid-13th century to 1900.

9. The British Library The national library of the United Kingdom, located in London. It is the largest library in the world by number of items held, with over 150 million items in its collection.

10. The Cotswolds A rural area in the west of England, known for its rolling hills, stone-built cottages, and picturesque villages. It is a designated Area of Outstanding Natural Beauty.

11. Edinburgh Castle A historic fortress located in the heart of Edinburgh, Scotland. It is one of the most famous tourist attractions in the city and has been used as a royal residence, a military base, and a prison.

12. The Lake District A mountainous region in the north-west of England, known for its lakes, fells, and hills. It is a popular destination for hiking, climbing, and outdoor activities.

13. The Giant's Causeway An area of about 40,000 interlocking basalt columns, the result of an ancient volcanic eruption, located on the north coast of County Antrim, Northern Ireland.

14. The Tower Bridge A combined bascule and suspension bridge in London, built from 1886 to 1894. It is one of London's most famous landmarks and offers views of the city from its walkways.

15. The Roman Baths An ancient Roman spa in Bath, England, that has been used since the 1st century AD. It is one of the most famous Roman remains in the UK and is a UNESCO World Heritage Site.