Colosseum

An engineering marvel and the largest amphitheatre in the world, Colesseum leaves everyone who sees it in awe. This monument stands tall as an example of the skills the roman empire had. It is an elliptical amphitheatre built of concrete with the original sitting capacity of 50,000 people. Its construction began during the reign of Emperor Vespasian in 70 CE. When completed in the reign of Titus, it was 48m high, 188m long and 156m wide. It was constructed for gladiatorial fights and animal fights. If you want to visit the Colesseum do not forget to book online tickets to avoid long lines.

Pantheon

A 2000-year-old Greco - Roman architecture still in use. Pantheon is the only building that has been in continuous use since the ancient times and boasts the world's largest reinforced concrete dome. It was designed in the Roman days to worship the Roman Gods but since the 7th Century, it is used by the Roman Catholics as the Church for St. Mary. The building has large Corinthian columns made of granite. It is said one can really appreciate the beauty of the site when it is raining and hearing watching the rain pouring down into the building from the hole in the ceiling is a once in a lifetime sight.

St. Peter's Basilica

One of the largest churches and the most renowned piece of architecture from the renaissance period is the St. Peter's Basilica. This magnificent building was designed by the greatest renaissance artists helped in the construction like Michelangelo and Bernini. Tradition and strong historical evidence hold that the tomb of Saint Peter, one of Jesus's apostles, is located directly below the altar of the church. Always be prepared to meet a large crowd at important festivals as the church being in the Vatican the Pope carries out most of the rites. Please be wary of what you wear as there is a strict restriction on what to wear.

Basilica di San Marco

The finest example of the Byzantine architecture the Basilica di San Marco attracts tourists from all over the world for its priceless treasures. It was originally a chapel for doges, Venice's chief magistrates and was only turned into a church in 1807. The interiors are a mix of cultures like the design based on a Greek cross, Byzantine onion-bulb dome and Egyptian marble walls.  Behind the main altar, containing the sarcophagus of St. Mark, an altarpiece is adorned with hundreds of emeralds, sapphires, rubies, pearls, and amethysts. The front of the building is rippled with five niched portals, each capped with more elaborate mosaics and stone arches. The church also contains a museum, displaying bronze horses brought here in 1204 as part of the loot from Constantinople in the Fourth Crusade.

Duomo di Milano

A marvel fo Gothic architecture, Duomo di Milano is a massive white marble church. It is the fist largest cathedral in the world. It is known for the marble, its hundreds of spires and thousands of statues carved on the exterior and a buttressed facade. It was constructed between 1386 to 1965. Climb up to the roof and you would get to enjoy the best view of Milan, especially at sunset. If you buy a special band at the entrance you can take photos inside.