2 Best Sights in Side Trips from Rome, Italy

At its peak, the ancient port town at this site was home to a cosmopolitan population of rich businessmen, wily merchants, sailors, slaves, and their respective families. Great warehouses were built here in the 2nd century AD to handle goods that passed through, notably huge shipments of grain from Africa. Indeed, the port did so much business that it necessitated the construction of insulae (apartment buildings) to provide housing for the city's growing population.

The increasing importance of nearby Portus and the inexorable decline of the Roman Empire eventually led to the port's abandonment. In addition, the coastline retreated over the millennia, and a 16th-century flood diverted the course of the Tiber. Tidal mud and windblown sand buried the ancient port town until the 19th century, when it was extensively excavated.

You can wander through the massive archaeological site and explore its curious corners, mosaic floors, fallen columns, and huge Roman amphitheater. The on-site Museo Ostiense displays sculptures, mosaics, and objects of daily use found here. There's also an on-site cafeteria. The recently excavated ports of Tiberius and Claudius are nearby and also well worth visiting.

Set below the ancient settlement of Tibur, this astonishingly grand 2nd-century villa was an exclusive retreat, where the marvels of the classical world were reproduced for a ruler's pleasure. Hadrian, who succeeded Trajan as emperor in AD 117, was a man of genius and intellectual curiosity, fascinated by the accomplishments of the Hellenistic world. From AD 125 to 134, architects, laborers, and artists worked on his dreamy villa, re-creating some of the monuments and sights that the emperor had seen on his travels in Egypt, Asia Minor, and Greece.

During the Middle Ages, the site was sacked by barbarians and Romans alike, and many of the statues and architectural features ended up in the Vatican Museums. Nonetheless, the colossal remains are impressive: the ruins rise in a garden setting of green lawns framed with oleanders, pines, and cypresses. Not surprisingly, Villa Adriana is a UNESCO World Heritage site, and it's one that has not yielded up all its secrets. Archaeologists recently discovered the site of the Temple of Isis, complete with several sculptures, including one of the falcon-headed god Horus. A visit to the villa, which sits outside town, takes at least two hours (carry water on hot days); maps dispensed at the ticket office will help you get your bearings.