These Are Some Of The World's Most Popular Attractions & Here's How To Avoid A Huge Waitlist

If you're planning to visit one of these popular sites during your next trip you'll want to plan ahead. A recent study has revealed the world's most "in demand" attractions and some require you to book over a month in advance.

Hotel chain Premier Inn has looked into over 100 of the top global attractions to see which ones you can visit on a whim and which ones you'll need to schedule before your travels.

Coming in at the top of the list is Germany's Neuschwanstein Castle. The fairytale palace is one of the "most iconic in the world" and is know for its majestic white towers and stunning natural surroundings. You'll need to book at least 37 days in advance if you want to visit this enchanting site.

Tied with Neuschwanstein Castle is Machu Picchu in Peru, which requires at least 37 days or sometimes up to three months of advanced booking, according to the study. There are over 1.5 million visitors to Machu Picchu each year and a capacity is enforced to preserve these ancient ruins.

Potterheads, take note! Second on the list of most "in-demand" attractions is the Warner Bros. Studio Tour in England. The tour takes you through sets, costumes, and more seen in the Harry Potter films and you'll want to book your tickets up to 34 days in advance. The Studio Tour came in at first place for the most "in-demand" attraction in the U.K, followed by London's Sky Garden.

Ghibli Museum in Japan came in at number three on the global list (book up to 30 days in advance), with the U.K's Sky Garden at number 4 (book up to 22 days in advance).

Here is the full list of in-demand attractions and how far in advance you should book them:

• Neuschwanstein Castle, Germany — 37 days
• Machu Picchu, Peru — 37 days
• Harry Potter Studio Tour, U.K — 34 days
• Ghibli Museum, Japan — 30 days
• Sky Garden, U.K — 22 days
• Mount Fuji, Japan — 16 days
• Santa Maria delle Grazie, Italy — 10 days
• The Van Gogh Museum, Netherlands — 10 days
• The Forbidden City, China — 8 days
• Big Ben, U.K — 8 days
• Borghese Galleria, Italy — 6 days
• The Catacombs, France — 6 days
• Anne Frank House, Netherlands — 6 days
• The Hermitage Museum, Russia — 6 days
• Walt Disney World, U.S — 4 days
• The Sistine Chapel, Vatican City — 3 days
• Statue of Liberty, U.S — 3 days