It was one of the several public baths in Rome, begun by the emperor Septimius Severus in AD 206 and completed by his son Caracalla in 216. Among Rome’s most beautiful and luxurious baths, designed to accommodate about 1,600 bathers, the Baths of Caracalla continued in use until the 6th century. The extant ruins are the most extensive of any surviving Roman bathing establishments and consist centrally of a block of large vaulted bath chambers, with courts and auxiliary rooms, surrounded by a garden with space used for exercise and games. There were three main bath chambers: the frigidarium, or cold room; the caldarium, or hot room; and the tepidarium, or lukewarm room. Between the frigidarium and the tepidarium was the great hall, roofed by an enormous vault with clerestory windows, a prototype of the vaulted naves of medieval churches. There were also open-air swimming pools. Marble was used lavishly, and sculpture, mosaics, frescoes, and other decorations ornamented the interior.

The Circus Maximus, largest of the Roman hippodromes was one of the largest sports arenas ever built. A U-shaped structure with seats on three sides and a low wall running down the middle of the arena around which the chariots raced, Built in the time of Julius Caesar (1st century BC) to seat an estimated 150,000 spectators. Enlarged by later emperors, it reached a maximum size under Constantine (4th century AD) of about 2,000 by 600 feet (610 by 190 metres), with a seating capacity of possibly 250,000, greater than that of any subsequent stadium. The Circus Maximus is the Ben Hur movie scenario. Two huge egyptian obelisks, trasnsported form Africa, stood in the middle of the central spine.

Appian Way, latin Via Appia, is the first and most famous of the ancient Roman roads, running from Rome to southern Italy. The Appian Way was begun in 312 BCE by the censor Appius Claudius. The Appian Way was celebrated by Horace and Statius, who called it longarum regina viarum, or “queen of long-distance roads.” As the main highway to the seaports of southeastern Italy, and thus to Greece and the eastern Mediterranean, the Appian Way was so important that during the empire it was administered by a curator of praetorian rank. The road averaged 20 feet (6 metres) in width and was slightly convex in surface in order to facilitate the drainage. The road’s foundation was of heavy stone blocks cemented together with lime mortar; over these were laid polygonal blocks of lava that were smoothly and expertly fitted together. The first few miles of the Appian Way are flanked by a striking series of monuments, and there are also milestones and other inscriptions along the remains of the road.

The Pyramid of Rome is the only surviving ancient Egyptian-style pyramid. The 36-metre high monument dates from the first century BC and was built as a tomb for the powerful Roman magistrate Caius Cestius. The Pyramid of Cestius was incorporated into into the Aurelian Walls. three centuries later, and an inscription on its white marble façade states that its construction took 330 days.

The keyhole of the Knights of Malta is one of the city’s more intriguing off-the-beaten-path sights. With its uninviting door and perfectly framed view of Saint Peter’s Basilica, it has become a favorite stop for travelers looking for alternative attractions in the city. It is common to see visitors queue up in front of the impenetrable door to take a peek, and many try to capture it with their camera — however, the view is one that can be truly experienced only in person.