London

Here's an ideal itinerary for 3 days in London:

Day 1:

• Start your day with a visit to the iconic Tower of London. This historic castle has served as a royal palace, prison, and even a zoo over the centuries. Be sure to see the Crown Jewels and take a guided tour with one of the Yeoman Warders.
• After the Tower, head over to the nearby Tower Bridge. You can walk across the bridge and take in the stunning views of the Thames River and the city skyline.
• For lunch, head to Borough Market. This bustling food market has been around for over 1,000 years and offers a wide variety of delicious food options.
• In the afternoon, visit the British Museum. This world-renowned museum has an incredible collection of artifacts from around the world, including the Rosetta Stone and the Elgin Marbles.
• End your day with a visit to the West End. Catch a show at one of the many theaters in the area, or simply stroll around and take in the lively atmosphere.

Day 2:

• Start your day with a visit to St. Paul's Cathedral. This stunning cathedral has been a symbol of London for over 300 years and offers incredible views from the top of its dome.
• After St. Paul's, head over to the nearby Tate Modern. This modern art museum is housed in a former power station and has an impressive collection of contemporary art.
• For lunch, head to the nearby Southbank Centre Food Market. This outdoor market offers a wide variety of food options and is located right on the Thames River.
• In the afternoon, visit the Houses of Parliament and Big Ben. Take a guided tour of the historic buildings and learn about the history of British politics.
• End your day with a visit to the London Eye. This giant Ferris wheel offers incredible views of the city and is a great way to see London from above.

Day 3:

• Start your day with a visit to Buckingham Palace. Watch the Changing of the Guard ceremony and take a tour of the palace's State Rooms.
• After Buckingham Palace, head over to the nearby Hyde Park. This beautiful park offers a peaceful escape from the city and has plenty of walking paths and green spaces to explore.
• For lunch, head to Covent Garden. This historic market has been around since the 17th century and offers a wide variety of food options.
• In the afternoon, visit the National Gallery. This world-renowned art museum has an incredible collection of paintings from some of the world's most famous artists.
• End your day with a visit to the Shard. This skyscraper offers incredible views of the city from its observation deck, and is a great way to end your trip to London.

I hope this itinerary helps you plan your trip to London! Let me know if you have any other questions or need any more recommendations.