© Shutterstock

Colosseum -

One of the most recognized ancient monuments in the world, the Colosseum, the original name of which is the Flavian Amphitheatre, is the largest structure left to us by Roman antiquity. Inaugurated in 80 CE and used for gladiatorial contests and public spectacles, the enormous venue could hold an estimated 50,000 to 80,000 spectators at various points in its history.

© Shutterstock 

Arch of Constantine -

Standing resplendent beside the Colosseum is the Arch of Constantine. A Roman triumphal arch dating back to 80 CE and dedicated to emperor Constantine the Great, it's the largest structure of its kind found anywhere in the world.

© Shutterstock 

Vatican City -

You could spend a whole day in Vatican City—the smallest independent state in the world—and still not have time to absorb all its riches. St. Peter's Basilica and St. Peter's Square is where to start exploring this fascinating papal enclave.

© Shutterstock 

Michelangelo's Pietà -

The Vatican's St. Peter's Basilica is the most renowned work of Renaissance architecture. Suitably, inside is Michelangelo's masterpiece 'Pietà' (pictured), one of the great treasures of the age.

© Shutterstock 

Sistine Chapel -

Michelangelo's most famous work, however, is the magnificent frescoed ceiling of the Sistine Chapel, the undoubted highlight of the Vatican museums' collections.

© Shutterstock 

Mausoleum of Augustus -

Recently reopened to the public after an extensive renovation is the Mausoleum of Augustus. Built by the first Roman emperor, Augustus, in 28 BCE on the Campus Martius, the site is now enclosed by a state-of-the-art visitor center that encircles the ancient tomb.

© Shutterstock 

The Pantheon -

Rome simply dazzles with historic attractions, and the Pantheon is the best preserved of all ancient Roman buildings. What you see is more or less how it looked 2,000 years ago. It's still in use today, as a Catholic church.

© Shutterstock 

Roman Forum -

To amble slowly through the Roman Forum is to explore what was once the very heart of the empire. While its original splendor is much diminished, this is where the most important government buildings once stood together with several temples, courts, market places, and public meeting places. What remains still impresses, and the Forum is where best to relive the history of ancient Rome and, indeed, Western civilization.

© Shutterstock 

Trevi Fountain -

It's said that if you toss a coin into the Trevi Fountain, it will assure your return to the "Eternal City." The decorative 17th-century water feature is one of the most famous fountains in the world, and has been immortalized in several notable films, among them 'Roman Holiday' (1953) starring Audrey Hepburn and Gregory Peck.

© iStock

Spanish Steps -

Rome's well-trodden Spanish Steps is a flight of irregular stairs and terraces that stagger up from Piazza di Spagna to meet the Trinità dei Monti church. They've become another favorite Instagram location.

© Shutterstock 

Santa Maria Maggiore -

Up there with St. Peter's Basilica as an ecclesiastical must-see, Santa Maria Maggiore is one of the city's most majestic churches. The interior is a visual feast of venerated religious artworks, a collection that includes the image of 'Salus Populi Romani,' depicting the Blessed Virgin Mary, and the extraordinary 13th-century mosaics depicting Old and New Testament themes that adorn the apse (pictured).

© Shutterstock 

Piazza Navona -

To sense how immense ancient Rome's public spaces were, wander through Piazza Navona, which still features the outline of the Roman stadium built here by Emperor Domitian. Used up until the Middle Ages as a festival and horse-racing venue, the historic square today serves as a picturesque city-center meeting point, and like the Trevi Fountain has served as a backdrop for a number of movies, including the Dan Brown thriller 'Angels & Demons' (2000).

© Shutterstock 

Borghese Gallery -

Rome's enviable portfolio of museums and art galleries include the Galleria Borghese. Set within a former villa, the gallery houses a substantial part of the Borghese Collection of paintings, sculpture, and antiquities, and is certainly worth investigating.

© Shutterstock 

Borghese Gallery collection -

Among artworks to admire is 'Boy with a Basket of Fruit' by the Italian painter Caravaggio and which dates back to 1593.

© Getty Images 

National Etruscan Museum of Villa Giulia -

A museum of the Etruscan civilization housed in Rome's Villa Giulia, this cultural facility holds one of the most famous exhibits in the city, the 'Sarcophagus of the Spouses' (pictured), a terracotta funerary monument unearthed in nearby Cerveteri, and dated back to 525–500 BCE. It's considered one of the great masterpieces of Etruscan art.

© Getty Images 

Capitoline Museums -

Rome's Capitoline Museums constitute a group of engaging art and archaeological museums, one of which contains the well-known 'Capitoline Wolf '(pictured). The bronze sculpture, probably cast in the 12th century, shows a she-wolf suckling the mythical twin founders of Rome, Romulus and Remus.

© Shutterstock 

Castel Sant'Angelo -

Immediately recognized for its towering cylindrical design, Castel Sant'Angelo was built in 123–139 CE, commissioned by the Roman Emperor Hadrian as a mausoleum for himself and his family. Sadly, much of the tomb contents and decorations have been lost since the building's conversion to a military fortress in 401 CE. Today the castle is a museum, the Museo Nazionale di Castel Sant'Angelo.

© Shutterstock 

Baths of Caracalla -

Romans took their washing seriously, a fact exemplified by the fortress-like ruins of the Baths of Caracalla. Far more than a place to take a dip, Caracalla featured sauna facilities, a sports arena, social rooms, gardens, libraries, and hairdressers. The site is still used today to host occasional music concerts and other cultural events.

© Shutterstock 

Archbasilica of Saint John Lateran -

The monumental cathedral church of the Diocese of Rome serves as the seat of the bishop of Rome, the Pope. No wonder then that it's one of the city's most opulently-decorated churches. The interior features a splendid octagonal baptistery, San Giovanni in Fonte—the world's oldest Christian baptistery.

© Shutterstock 

Appian Way -

"All roads lead to Rome," according to the proverb. In antiquity, walking the Appian Way, or Via Appia Antica, out of the city would have taken you all the way to Brindisi, in southern Italy. One of the earliest and strategically most important Roman roads of the ancient republic, this historic highway still exists in part, with many sections of the original road beyond Rome's environs having been preserved for posterity.

© Shutterstock 

Catacombs of Santa Domitilla -

Delving under Rome's streets brings its own rewards. Sited near the Appian Way, the Catacombs of Santa Domitilla are the largest and among the most impressive in the area. An underground Christian cemetery, the catacombs still hold the remains of humans. The walls in are decorated with images reflecting the life of bakers (pictured), grape vines, Jesus with the apostles, Noah's ark, and Daniel with the lions.

© Getty Images 

Baths of Diocletian National Museum -

Ancient Rome's other big former imperial bathing site, Terme di Diocleziano is today the Baths of Diocletian National Museum. Besides a museum, the site is expansive enough to hold two churches and large parts of a Carthusian monastery.

© Shutterstock 

Baths of Diocletian National Museum collections -

Greek and Roman sculpture, pre-Christian and later sarcophagi, and some truly remarkable and well-preserved mosaics and frescoes greet visitors to the museum.

© Shutterstock 

Via Condotti -

If you're up for a bit of retail therapy, head over to Via Condotti, set off Piazza di Spagna in the city's centro storico ("historic quarter"). The fashionable street is home to some of the world's most famous designer boutiques including Gucci, Dior, Valentino, Hermès, and Armani.

© Getty Images 

Antico Caffè Greco -

Also located on Via Condotti is Antico Caffè Greco, founded in 1760 and the oldest café-bar in Rome and second oldest in Italy, after Caffè Florian in Venice.

© Getty Images 

Trajan's Market -

Known as Mercatus Traiani, this ancient market place is often referred to as the oldest shopping mall in the world. Completed in 110 CE and named for Trajan, one of the greatest of Roman emperors, it would have sold a variety of everyday wares including fruits, vegetables, fish, wine, oil, and spices.

© Shutterstock 

Pyramid of Cestius -

Rome is perhaps the last place you'd expect to stumble across an Egyptian pyramid, but then again the city is full of surprises. The Pyramid of Cestius was most likely built between 18 and 12 BCE as a tomb for a wealthy Roman resident in the wake of the Roman conquest of Egypt in 30 BCE. It's the only 'Egyptian' pyramid found in Europe.

© Shutterstock 

Piazza Venezia -

Piazza Venezia is a famous square in Rome. But it's also notorious for being the location of "Mussolini's Balcony." It's from here (marked by the flags in the photograph) that Italy's fascist dictator, Benito Mussolini, made some of his most memorable speeches to the crowds below. On one occasion, Il Duce was joined on the balcony by Adolf Hitler. The ornate palace, Palazzo Venezia, that dominates one side of the square, served as Mussolini's headquarters throughout the 1930s.

© Shutterstock 

Pons Fabricius -

The oldest Roman-made bridge in the city, Pons Fabricus still exists in its original state. Spanning the Tiber River, it was constructed in 62 BCE.

© Shutterstock 

Marcus Aurelius Column -

Built in honor of Roman emperor Marcus Aurelius and completed in 193 CE, Marcus Aurelius Column in front of Palazzo Chigi is remarkable for its spiral relief, which tells the story of Marcus Aurelius' wartime exploits, including the conflict in Germania, part of the Marcomannic Wars.

© Shutterstock 

Parco degli Acquedotti -

A good excuse to leave the hustle and bustle of the city center and head into the Roman countryside is to admire the ruins of two colossal ancient aqueducts, Aqua Claudia and Aqua Marcia. Both are found in the Parco degli Acquedotti, or Aqueduct Park.

Sources: (World History Encyclopedia) (Smarthistory) (Livius)

See also: The most impressive arches and aqueducts in the world

© Shutterstock