The ancient Flavian Amphitheater was built by the Flavian emperors in 70 C.E. as a gift to the Roman people. As the largest Roman theater ever built, it was designed to house over 50,000 people, and had played host to gladiator games, plays and even public executions. Purchase skip-the-line tickets online to avoid long lines at the door, or join guided tours which allow for special access to restricted areas. While here, you might want to visit the adjacent Palatine Hill and Roman Forum as well. – Tripadvisor

Dedicated to the seven planetary divinities and featuring an interior of gorgeous marble, the Pantheon is one of the most impressive monuments of Augustan Rome.

The centerpiece of Milan, the Duomo is one of Europe’s greatest architectural and cultural landmarks. As Italy’s largest church and one of the largest in the world, it took over 600 years to build. Today, the Duomo has a capacity of 40,000 people and is home to the world’s second-largest organ. Admire the wide selection of religious art on display inside, or marvel at the 3000 statues that line its Gothic exterior. Be sure to join one of the available Duomo tours, which include art tours and even rooftop tours, where you might be able to see as far as the Italian Alps. – Tripadvisor

Certainly the most famous and photographed fountain in Rome, legend has it that whoever throws a coin into the pond will return to Rome.

This neoclassical-style piazza built by Giuseppe Poggi in the 19th century offers some of the best panoramic views of Florence's historic center. The plaza is also home to several replicas of Michelangelo's famous sculptures, including David and the Medici Chapel statues. To get to the piazza, you'll need to climb up a steep hill, but the unobstructed views are worth it. Sunset is a popular time to visit when the plaza is bathed in golden light. You can take a taxi or car tour up the hill, or for a unique experience, pass by the piazza on a Vespa tour through Tuscany from Florence. – Tripadvisor

Arguably one of the finest Cathedrals in the entire world, St. Peter's is the spiritual center of the Vatican and the product of many of Italy's great Renaissance's architects, among them Bramante, Raphael and Michelangelo.

One of the great museums of the world, the Uffizi houses the premier collection of Italian Renaissance art, featuring works by such masters as Botticelli, Titian, Michelangelo and da Vinci.

For sheer belle époque splendor, this extravagant 19th-century glass-topped, barrel-vaulted tunnel serves as a lively, noisy and colorful shopping mall, teeming with life and inviting you to people-watching from the tables that spill from the Galleria's many bars and restaurants.

With more than five miles of corridors, this vast complex of museums chronicles the history and accomplishments of mankind over the last 2000 years, featuring classic masterpieces such as Rodin's "Thinker" and the Sistine Chapel.

A masterpiece of Gothic architecture, the building and its sculptural decoration date from various periods. The interior, with works by artists such as Titian, Veronese, Tintoretto, A.Vittoria and Tiepolo, includes vast council chambers, superbly decorated residential apartments, and austere prison cells. Along the facades of the Palace run loggias that overlook St. Mark’s Square and the lagoon. The combined entrance ticket to the St. Mark’s Square Museums grants access to the Doge’s Palace, Museo Correr, Museo Archeologico Nazionale and Monumental Rooms of Biblioteca Marciana.