1. Florence
   Istanbul
2. Athens
   Moscow

The Acropolis is one of Athens' – and the world's – most visited sites, rich in the history of ancient Greece. The Acropolis has been many things throughout its history, including a center of religion, a mythical home for the gods and, now, a tourist attraction.

1. Paris
   London
2. Dublin
   Berlin

The tower formerly known as simply Clock Tower was renamed Elizabeth Tower several years back in honor of Queen Elizabeth II. Big Ben is actually a bell inside the tower, the largest of five, though the entire structure is often referred to as Big Ben.

1. Coliseum
   Eiffel Tower
2. Parthenon
   Brandenburg Gate

The Eiffel Tower stands 1,063 feet over the City of Lights, contributing to that nickname with more than 20,000 lights that are lit every evening. The Eiffel Tower is one of the most visited monuments in the world every year.

1. The Colosseum
   The Athenaeum Hotel
2. The Aegean
   Warwick Castle

The Colosseum, located in Rome, was the one-time site of gladiator fights like you might have seen on movies like "Gladiator," starring Russell Crowe. It remains the largest amphitheater ever built.

1. Brussels
   Dublin
2. Venice
   Vatican City

Though it may feel like a part of Rome, Italy, Vatican City is its own city-state. It is the home of the current Pope, who is the leader of the Roman Catholic Church. Though only approximately 1,000 people call it home, it welcomes more than five million visitors annually.

1. Red Square
   Tiananmen Square
2. Malbork Castle
   Kronborg

Red Square has a unique and varied history. It began as a slum just outside the walls of the Kremlin, hosted numerous public executions and more recently, it has been the site of parades, fashion shows and festivals. The location is originally named "Krásnaya," which actually means "beautiful" in Russian.

1. Doric Path
   Brandenburg Gate
2. Charles Bridge
   Carl Gotthard Langhans

Brandenburg Gate, designed by Carl Gotthard Langhans, has represented both the division and reunification of East and West Berlin and Germany as a whole. The gate is an architectural masterpiece, having been erected in the 18th century.

1. The Balboa
   The Pisa Cathedral
2. The Eiffel Tower
   The Leaning Tower

The Leaning Tower of Pisa, which would have just been known as the Tower of Pisa if not for its structural deficiencies, started experiencing difficulties as soon as construction began. History tells us the tower was built on ground that was too soft, and rather than stop construction, workers tried to remedy the situation by making the remaining floors shorter on the uphill side. Needless to say, that didn't work.

1. Cliffs of Moher
   Cairngorms
2. Stonehenge
   The Verdon Gorge

Stonehenge has been a mystery that humans have been trying to figure out ever since it was constructed around 3000 B.C. Some theories have included it being the work of Merlin the Wizard; others have blamed the Devil. More recent theories involve aliens and UFOs.

1. The Louvre
   The Eiffel Tower
2. The Arc de Triomphe
   The Paris Underground

The Louvre is an art lover's dream, featuring more than 35,000 paintings and sculptures. Its entrance is just as captivating, taking on the form of a glass pyramid which reaches 71 feet into the air. It was designed by I. M. Pei, a renowned architect.

1. Paris
   London
2. Munich
   Helsinki

Notre-Dame Cathedral, an example of French Gothic architecture, sustained significant damage in a spring 2019 fire. Estimates for its repair range in the neighborhood of $8 billion and up to five years to complete.

1. Old Bridge
   Charles Bridge
2. Rialto Bridge
   Tower Bridge

The Tower Bridge in London is so-named for its proximity to the Tower of London. It was built in the late 1800s, and more than 50 design submissions were received for its construction, with the winning design belonging to Sir Joseph Bazalgette.

1. The Caldera Of Santorini
   Mykonos
2. The Meteora
   The Parthenon

The Parthenon is a part of the Athens site known as the Acropolis. The structure itself is the best known of the Acropolis' buildings and was built in dedication to Athena, the goddess of warfare and wisdom, who was believed to protect the city of Athens.

1. Wagner
   Berlin
2. Bavaria
   Frankfurt

Neuschwanstein Castle is the thing that Disney dreams are made of, serving as the inspiration for the castle in "Sleeping Beauty" and also being used to draw ideas from for Walt Disney World's Cinderella Castle.

1. Rome
   Verona
2. Tuscany
   Paris

Rome's Trevi Fountain is one of its most famous tourist attractions, with many attempting the backward coin toss hoping to get a return trip to Italy's capital city. The fountain itself is a depiction of Neptune and his chariot pulled by sea horses.

1. Naples
   Milan
2. Vatican City
   Genoa

The Vatican City is home to the Sistine Chapel. Its ceiling was famously painted by renowned artist Michelangelo and includes the fresco painting, "The Creation of Adam," an image of God reaching out to touch mankind.

1. Debrecen
   Eger
2. Budapest
   Sopron

The Hungarian Parliament Building, designed by Hungarian architect Imre Steindl, is Budapest's tallest building. It contains nearly 700 rooms and more than 12 miles of stairs, so be sure to pack your tennis shoes.

1. Amsterdam
   Dublin
2. Prague
   Brussels

Amsterdam, the capital of the Netherlands, is home to the Van Gogh Museum, which hosts more than one million visitors annually. Guests to this museum can view five different periods of his life and work, ranging from The Netherlands to Saint-Remy.

1. Prague
   Brussels
2. Florence
   Paris

Florence is home to the Duomo, known to locals as il Duomo di Firenze, a cathedral with the world's largest-ever brick dome. The design and construction of the dome were considered revolutionary and ahead of their time when the build was started in 1296.

1. Pitti Palace
   Windsor Castle
2. The National Art Gallery
   Buckingham Palace

Buckingham Palace is both the official royal residence of Queen Elizabeth, located in the heart of London. Its 775 rooms include more than 200 bedrooms and nearly 80 bathrooms. Buckingham Palace is guarded by individuals known as the Queen's Foot Guards.

1. Istanbul
   Budapest
2. Bucharest
   Tehran

Istanbul is the location of Hagia Sophia, a one-time cathedral and mosque turned museum. Its design is a representation of Byzantine architecture, with its massive dome situated on a square base.

1. Grindavík
   Selfoss
2. Akureyri
   Akranes

Grindavik is home to the world-famous Blue Lagoon, where visitors can pay to soak in the geothermal spa. It is considered one of the 25 wonders of the world and is located in the southwestern portion of Iceland.

1. Santander
   Valencia
2. Madrid
   Barcelona

Park Güell offers views of the Barcelona skyline from its urban park location, as well as green spaces and walking trails. It also features art by Antoni Gaudi himself, described by many as enchanting.

1. Florence
   Hamburg
2. Bucharest
   Normandy

The history of Mont Saint-Michel includes the tale of the archangel Michael himself demanding that a great church be built on the island. Today, tourists can visit the island where the abbey is located by taking a 1.5-mile walk from nearby parking.

1. Alhambra
   Citadel of Aleppo
2. Malbork Castle
   Mehrangarh

Its name, Alhambra, alludes to the place and fortress complex's reddish-tinted walls. Having gone through periods of disrepair and renovation, the complex is now one of Spain's most popular tourist attractions.

1. Amsterdam
   Vienna
2. Prague
   Brussels

Vienna Zoo is the oldest recorded zoo in the world, dating back to 1752. It is located on the grounds of Schönbrunn Palace in Vienna, which also played host to Mozart's first concert when he was just 6 years old.

1. Chamonix
   Cannes
2. Marseille
   Nice

Chamonix, France, is home to Aiguille du Midi, which includes a room made of glass on three sides (and under your feet!). From here, you can see the highest mountain peaks in western Europe.

1. Mosque of Cordoba
   Verdon Gorge
2. Granada Cathedral
   Sagrada Familia

Sagrada Familia, a Catholic church in Barcelona, isn't expected to be completed until 2026, but that isn't stopping tourists from checking it out. If it's completed that year, it will mark 100 years following the architect's death.

1. The Colosseum
   The Parthenon
2. The Pantheon
   The Sistine Chapel

The Pantheon is considered to be the best maintained of Rome's ancient buildings. Today, it functions as a Catholic church and is the burial site for Renaissance painter Raphael as well as two Italian kings.

1. Omsk
   Moscow
2. Sochi
   St. Petersburg

The Church of Our Savior of Spilled Blood is frequently pictured in literature about St. Petersburg, thanks to its bulb-shaped domes and colorful exterior. During World War II, this famous landmark was used as a storage house for food.

1. Amsterdam
   Budapest
2. Vienna
   Prague

Located in Prague, Czech Republic, Charles Bridge is an epic tourist destination for its romantic location boasting a great place to view the sunrise and its 30 statues installed along the stone bridge itself.

1. Royal Palace of Madrid
   Belém Tower
2. Castell
   Aqueduct of Segovia

Belém Tower sits as an iconic building in Lisbon, Spain, having served as both a fortress to protect the city's harbor and as a starting point for many of the discovery voyages that were initiated from Spain. Today, it is open to tourists.

1. Valencia
   Seville
2. Barcelona
   Madrid

El Escorial Monastery was commissioned by Philip II to serve as a burial location for Spanish rulers. With the exception of two or three monarchs, it has done just that since its completion in 1567, while also serving periodically as a palace, library, museum and hospital.

1. Granada
   Sintra
2. Madrid
   Lisbon

Sintra, Portugal, is the site of this colorful castle that draws elements from many different architectural styles. Its eclectic style is the work of a German architect known as Wilhelm Ludwig von Eschwege.

1. Lugano
   Lausanne
2. Zermatt
   Bern

Located in Zermatt, Switzerland, the Matterhorn sits on the Switzerland-Italy border. It is considered one of the most deadly mountains out there, rising 15,000 feet into the sky. It has claimed the lives of more than 500 people who have tried climbing it.

1. Sphinx Observatory
   Leaning Tower of Pisa
2. Siding Spring Observatory
   The Shard

The Sphinx Observatory, named after the summit on which it's located, sits 11,716 feet above sea level. Also called the "Top of Europe," it is the highest-altitude human-made structure in all of Europe. The observatory is used to help scientists study different branches of science, including meteorology and astronomy.

1. Clare
   Dublin
2. Limerick
   Galway

The Cliffs of Moher rise 700 feet over the Atlantic Ocean from their highest point. They are often depicted in Irish art, contributing to the natural wonder being Ireland's most visited tourist attraction.

1. Veytaux
   Bern
2. Geneva
   Lucerne

Chateau de Chillon, also known as Chillon Castle, is located on Lake Geneva in Switzerland. It is said to have inspired many writers and artists, including "The Prisoner of Chillon" by Lord Byron.

1. Salzburg
   Hallstatt
2. See
   Werfen

Werfen, Austria, is home to Eisriesenwelt, caverns of ice that live more than 1,300 feet below the ground. Legend has it that some people believed Eisriesenwelt was the "icy entrance to Hell."

1. Lucerne
   Berlin
2. Rome
   Paris

The Arc de Triomphe stands as a monument to fallen soldiers from the French Revolutionary and Napoleonic Wars. Inscribed on it are the names of French generals and, located beneath, you'll find France's Tomb of the Unknown Soldier, a memorial to fighters in World War I.