Tickets for Priscilla Catacomb: Guided Tour

Built between 1609 and 1613, this opulent structure - fountains, gardens, pink marble walls, frescoed ceilings - seems ideally suited to house one of the world's best collections of art. And that was exactly what it was built for. Architect Flaminio Ponzio designed it for the cardinal and art collector Scipione Borghese, who wanted a party villa on the edge of town where he could house his enormous collection of priceless art. In 1901, the collection (and the gallery, and the park that surrounds it) was acquired by the Italian government, and opened to the public. As a museum, Galleria Borghese punches well above its weight with an impressive hit rate of masterpieces. Sculptures by Bernini and Canova, paintings, by Caravaggio, Raphael and Titian... the list goes on.

The Renaissance-era St Peter's Basilica is one of the largest churches in the world (and the home-church of the Pope). Highlights include the dome (the biggest in the world), Bernini's Baldacchino (the centerpiece of the church), and Michelangelo's Pietà (the only artwork he ever signed). For both the pious and the casual visitor, a trip to St. Peter's is an awe-inspiring trip into the heart of Vatican City.

The towering cylinder of Castel Sant'Angelo, and its statue of Archangel Michael, is an instantly recognizable silhouette on the banks of the Tiber. Initially built as a mausoleum for Emperor Hadrian and his family, its purpose has changed many times over the years, from a fortress, a residence, a prison, and now a museum.