Few nations as small as the UK have as many must-see sights. London alone is made up of some of the most iconic structures, palaces, and landmarks in the world. But even looking beyond the capital, England, Scotland, Wales, and Northern Ireland are hotbeds of international tourism.

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Standing as the worlds sixth-largest tourist destination, the UK receives over 40 million visitors each year. Because of this, it's fairly certain you'll run into massive crowds. People are going to be unavoidable when you visit, so be sure to jot down these 10 most crowded locations before your plane lands at Heathrow.

10 Buckingham Palace - London

One of the most iconic royal palaces in the world, Buckingham Palaces sits in the heart of London. Home to the Royal Family for nearly 200 years, Buckingham Palace is currently the London home of Queen Elizabeth II. This alone will attract sightseers galore, but it is the almost daily pageantry of the changing of the guard that attracts most visitors.

The Changing of the Guard is a constant ceremony where royal guards parade across the grounds of Buckingham Palace. This bit of royal regalia attracts thousands each day, crowding the memorial to Queen Victoria and the surrounding area. Buckingham Palace alone attracts 15 million tourists a year, making it the most populated attraction in London.

9 Leicester Square - London

London's parks and squares are some of the most visited in the world. In the belly of the west end is Leicester Square. This green area is nestled around theaters, Chinatown, and tourist traps on all sides. What with being blockaded by some of the most essential tourist sites in the city, Leicester square is not as serene as most city parks.

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Not only are there tons of museums, casinos, and restaurants to visit, but the square is also filled with film and theater premieres constantly. Be prepared for crowds wanting to capture a glimpse of their favorite stars.

8 Roman Baths - Bath

A perfect day trip from London is just a short hours train to Bath. This Georgian paradise is home to beautiful architecture, a gorgeous cathedral, and one of the most well preserved roman sites in the UK: the Roman Baths.

This site is where the city gained its name, thanks to the large baths, saunas, and springs, left from Roman times. It is certainly the most visited site in the city, but nowhere near the size of crowds in the capital. But, due to the closed quarters of many of the exhibits, the crowds feel double in size. Like many UK sites, it is better to visit in the offseason, when tourists numbers are low.

7 Piccadilly Circus - London

Piccadilly Circus is to London as Times Square is to New York City. This hub of advertisements, restaurants, street art, and more is a must-see for every tourist, at least once. It's the ultimate center of London, playing home to multiple underground entrances, as well as constant busses and traffic.

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While the excitement of this city center is certainly one to witness, be prepared for some of the biggest crowds around. Out of all the public squares and pedestrian areas, this has to be one of the most populated. The iconic Shaftesbury Memorial Fountain with the winged eros at the center is almost always covered in a mass of resting tourists.

6 Tower Of London - London

The Tower of London is one of the most important historical spots in the UK. The oldest part of the structure lies in the white tower and is actually the oldest building in London. Hosting the crown jewels, the iconic raves, and regaled beefeaters, the Tower is a quintessential stop on any UK visit.

But be wary, the Tower is infamous for more than just its bloody past. The crowds at the Tower of London are known the world over. It's the most visited paid attraction in the nation, garnering 2.86 million visitors each year.

5 Covent Garden - London

It's always surprising that tourists will go all the way across the world just to shop. But, if Covent Garden is your retail therapy destination, no one would blame you. Covent Garden is one of the best and oldest retail centers in the world. Full of food, drink, shopping, and entertainment, it is a one-stop-shop for tourists in London.

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Unsurprisingly, paring the boutique shops and entertaining street performers results in massive crowds. In locations such as this, be sure to prepare yourself for the masses, and not to mention those who take advantage of crowds. Like many of these public spaces, big crowds mean pickpockets, especially when shopping is involved.

4 Brighton Beach - Brighton

Attracting British holidaymakers and international travelers alike, Brighton Beach is the perfect summertime getaway in Britain. Located at the bottom of England right against the English Channel, Brighton is replete with its beach and famous victorian boardwalk.

The English weather means beach visits are a rarity. So, when the sun does finally decide to show its face, the beach at Brighton will become a nightmare of epic proportions. Take advantage of those cloudy days when you visit this waterside locale.

3 Churchill War Rooms - London

One of the best historical sites in London are the Churchill War Rooms and Museum. Preserved just as they were during the war, this museum gives visitors the chance to walk through the halls of Winston Churchill's wartime headquarters.

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Not only that, but the site also has its own Winston Churchill museum, showcasing the life of this 20th-century icon. While it is certainly worth the price of admission, the actual war rooms are fairly cramped. So, if you plan to visit, do so in either the slower months or hope you're lucky. If visitation is up even a bit more than normal, these war room hallways become a tourist traffic jam.

2 Borough Market - London

Like Covent Garden, Borough Market is one of the largest shopping hubs in the city. Instead of major retailers though, this market hosts some of the best street food around. Anything you could dream of devouring can be found in this nine hundred-year-old market, from Cornish Pasties to Jamaican cuisine.

Of course, with this much good food right on the Southbank, there are sure to be people everywhere. Be prepared for ravenous crowds shuffling from stall to stall. Remember to bring an empty stomach and lots of patience.

1 Westminster - London

The Westminster area of London is probably the first image that comes to mind when someone mentions the UK. The combination of Big Ben, Parliament, Westminster Abbey, the Westminster Bridge, and the London Eye all make up this area. With so many must-see sights located in one place, you can be more than sure to expect more than your fair share of crowds.

This is one that is pretty unavoidable. If you plan to visit London, all you can do is prepare for the biggest crowds of your trip or just plan at going in the early morning.

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