The world's most popular tours for travellers

Summer is here and with it, millions of tourists will be embarking on their next travel adventures.

Viator, a travel tours company, recently revealed the top tours booked around the world.

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It found that the most popular tours in the USA are the Grand Canyon and the Hoover Dam.

The Hoover Dam tour leaves from Las Vegas and the day trip guarantees scenic views.

The world's tallest building is also a hot ticket. The Burj Khalifa Tour in Dubai provides panoramic views of the desert city.

When it comes to the UK, a day trip from London to Stonehenge is one of the top destinations in Europe and you can even book a private tour of the famous rock formations.

And hitting the top of the list is a tour of the world's smallest country: The Vatican City is the most popular tour booked by tourists in 2016.

If this sounds like it's right up your street you can skip the long lines and enjoy the Vatican's museums, Sistine Chapel and St. Peter's Basilica.

Other tours to popular attractions available on the site include the Colosseum, Alcatraz and Mount Fuji among others.