I'm from Rome. Visit these 9 underrated, less-crowded monuments instead of the Colosseum and the Vatican.

Located steps away from the iconic Piazza Navona square is Palazzo Altemps, a 15th-century aristocratic villa that was inhabited by the Altemps family for centuries.

It may look plain from the outside, but inside, there is a large courtyard framed by marble statues and rooms and ceilings decorated with ornate frescoes and mosaics.

Palazzo Altemps also houses a large collection of ancient Roman and Greek sculptures that once belonged to several Roman noble families.

I've noticed very few people there the times I've visited, and it felt like I had the entire palazzo to myself despite it being in one of the city's busiest areas.

If you've ever wondered how the Romans bathed, then the Baths of Diocletian are a must-see site.

The massive archeological complex, located near the Termini train station, was built by the emperor Maximian between 298 and 306 CE.

At its height, the roughly 32-acre complex could welcome up to 3,000 people. Today, the area comprises the remains of the baths, a museum, and a church and charterhouse.

Much of the space is open to the elements, so I would recommend only visiting on a nice day.

Trajan's Market, widely considered to be the world's first covered shopping mall, is one of my favorite ancient Roman sites in the city because of its history and well-preserved state.

It sits squarely along the Via dei Fori Imperiali, a long road stretching from the Colosseum to Piazza Venezia.

Built by Emperor Trajan around 105 CE, the multi-level structure once housed a library, offices, and shops.

The remains of wall frescoes and geometric floor mosaics can still be seen in the ground-floor stalls. At the top of the structure is, in my opinion, one of the most beautiful panoramic views of Rome.

Towering over the Tiber River just outside of the Vatican City is Castel Sant' Angelo. The ancient structure was originally built as a mausoleum for the Roman Emperor Hadrian around 139 CE.

Over the centuries it was used as a fortress, military barracks, and a prison, the remains of which can still be seen inside today.

I've been visiting the site since I was little, and love the panoramic view of the Tiber River and the dome of Saint Peter's Basilica from its top, especially at sunset.

I also enjoy the structure's small, open-air café and restaurant overlooking the scenery, which is ideal for those who may need a break from all the sightseeing.

Positioned in the center of one of the city's busiest intersections is a small archaeological area made infamous for being the location of Julius Caesar's assassination.

The archaeological complex holds the remains of four temples and a theater dating back to the Republican period.

The archaeological area also serves as a cat sanctuary for the city's strays — it's not uncommon to see groups of them lounging around the ruins. They're cared for by local volunteers who accept donations by way of an Adoption at a Distance program.

The Parco degli Acquedotti, or the Park of the Aqueducts, extends for nearly 600 acres just outside of Rome.

Also a popular spot for cycling, dog-walking, and picnics, the massive park comprises the remains of ancient Roman aqueducts that carried fresh drinking water from the mountains and into the city.

It's one of my favorite places to visit on warm spring or summer days for a walk and to escape the city for a bit, and it's particularly beautiful at sunset.

This museum in Rome's historic center houses the city's largest private collection, which was assembled by the Doria, Pamphilj, Landi, and Aldobrandini families.

The palace is currently owned by the Doria Pamphilj family and is located just off Piazza Venezia, on the trendy Via del Corso.

Galleria Doria Pamphilj is known for its ornate, frescoed walls and antique furnishings, as well as a large collection of oil paintings and sculptures from masters such as Velàzquez, Caravaggio, and Bernini.

The mid-16th century Villa Medici is a haven for art lovers.

The villa is atop Pincio Hill, which offers one of the most romantic panoramic views. It sits on many acres of green area, including various Renaissance-style gardens decorated with pine trees, flower beds, obelisks, and fountains.

Although Villa Medici is famous for housing thousands of historic drawings, prints, sculptures, tapestries, and furniture pieces collected by noble families over the centuries, its crown jewel is its decorative arts library.

About 15 feet below Piazza Navona lie the nearly 2,000-year-old ruins of the Stadium of Domitian. It once housed Roman athletics and gladiator games and is thought to have seated at least 30,000 people.

This is, in my opinion, one of the most overlooked ancient Roman sites in Rome, likely because its unassuming entrance is tucked away and easy to miss.

As it's underground and much cooler, it's one of my favorite sites to visit during the city's scorching summers.