The commercial, political and religious centre of ancient Rome, the Forum spreads along the valley floor between the Capitoline and Palatine hills. It was constructed over about 900 years, with Republican buildings sitting in juxtaposition with temples from the Imperial era. At its peak, it must have been awfully crowded - like something dreamed up by Monty Python. The site's disrepair and disintegration into pastureland mirrored the fall of the Roman empire, and excavations have been underway since the 18th century.

The Forum is entered from the piazza leading from the colosseum - that house of horrors cum marble quarry, also known as the Flavian Amphitheatre. You immediately enter another world: the past. Columns rise from grassy hillocks and repositioned pediments and columns aid the work of the imagination. Just some of the many must-sees include the Arch of Septimus Severus, the Temple of Saturn, the House of the Vestals, the Temple of Antoninus & Faustina and the Arch of Titus.
From the Forum, you can climb the Palatine - where the wealthy and powerful built their palaces and personal temples. A layer of medieval churches and Renaissance gardens and villas transformed the hilltop ruins into a magical, ivy and agapanthus-covered land of grottos and secret vistas. Look out for the House of Livia, the Domus Augustana, the Palace of the Flavians and the ruins of the Baths of Septimus Severus. You can look down on ruins of the Circus Maximus, though not much remains of what was once a chariot racetrack big enough to hold more than 200,000 spectators.