The massive structure standing at the southeast end of the Circus Maximus serves as the headquarters of the United Nations Food and Agriculture Organization (FAO). This building plays a major role in global efforts to fight hunger and promote sustainable agriculture.
The rooftop of the FAO offers what many consider the most impressive views across Rome. Visitors can see sweeping panoramas of the city’s historic landscape, with monuments and ancient sites stretching out in every direction. However, access is tightly controlled. Entry to the roof is limited to those who have permission or personal connections with someone working inside, due to strict security measures.
Source - https://en.wikipedia.org/wiki/FAO_Headquarters
Erected in 203. You can see it close up from Via della Curia also (without entering the Forum).
A tomb for the wealthy Gaius Cestius, who died in 12 BC. Admission to the monument only by guided tours on specific dates (2nd and 4th Saturday every month, and in combination with a ticket to the Museum of Via Ostiense also on the 1st and 3rd Saturday of every month).
Small collection of railway carriages and related stuff. Really just for those with special interest in the topic. Entrance through the station if the main entrance is closed.
Early Roman houses dating back to the 1st century, believed to be homes of early Christians. Well-preserved frescoes and a small museum.
Rome's museum of contemporary art, housed in a former industrial complex. Rotating exhibitions, each one usually lasting about 4 months. The MACRO Testaccio exhibition space is located in Aventino-Testaccio.
This is a treasure-trove of art. There are a couple of paintings by Caravaggio: "The Crucifixion of Saint Peter" and "The Conversion of Saint Paul" (in a dim alcove to the left of the altar, both at right angles to the viewer, with a machine wanting €2 to switch on the lighting) together with a sculpture by Bernini, frescoes by Pinturicchio and mosaics by Raphael. Part of the Dan Brown tour, this church featured in Angels and Demons, although the Vatican did not allow filming inside.
A 5th-century basilica, simply and attractively decorated. The wooden door, of which 18 carved panels of scenes from the Bible survive, is believed to date from the church's construction.
This palace of the 16th century was erected by the famous Medici family. It was the residence of Cardinals Giovanni and Giuliano Medici, later Pope Leo X. and Clement VII. Catherine de Medici, Pope Clement VII's niece lived here until her marriage in 1553 with Prince Henry, the son of King Francis I of France. The palace is named after Madama Margerita of Austria, the illegitimate daughter of Emperor Charles V. Since 1871 it has been the seat of the Italian Senate.
Caffarella Park covers an area of 339 ha and is part of the larger Appia Antica park. It contains both a working farm and numerous Roman ruins, some quite well preserved and is a great place for a stroll or cycle away from Rome’s traffic.
A lovely, if somewhat run-down park (parts of it are blocked due to the poor state of the roads) with statues and a great view on the city.
Brand new museum designed to celebrate the art and architecture of the 21st century.
Next door to Santa Croce. A collection of around 3000 pieces, although only a third of these are displayed.
The western end of the ancient Via Appia road connecting Rome to Brindisi in the heel of Italy, and as such the third world heritage site in Rome together with the Old Center and the Vatican. As such it's an important historical location, even if the remains of the gate aren't as impressive as the city's major sites. As Via Appia heads southeast out of Rome, and after a few kilometers the route is officially named Via Appia Antica and starts looking more historical: it gets narrow as a city street, the asphalt is replaced by a rock surface and the road is lined with parks and park-like areas and walled old buildings. This section has been described as the world's longest museum.
The renamed Rome Zoo, one of the oldest in Europe, founded in 1911. On the edge of the Borghese Gardens, a short, well-signposted walk from the Gallery. They try hard, but San Diego this isn't. If you are a regular zoo-goer you will be disappointed.