Colosseum viewed from Palatine Hill.

The Colosseum is probably Rome's most recognisable building.

Colosseum at night, surrounded by traffic.

Arch of Constantine, viewed from the Colosseum.

Trevi Fountain, filled with thousands of euros each day by tourists.

Pantheon interior, the most well preserved Roman building.

Roman Forum, containing the ruins of the Empire's central business district.

Temple of Antoninus and Faustia, built in the 2nd century.

Trajan's Forum at night, dominated by Trajan's column.

Ruins of a stadium on the Palatine Hill, adjacent to the Roman Forum.

Circus Maximus, with the Palatine Hill in the background.

Victor Emmanuel Monument, a 19th century monument despised by the locals.

Area Sacra. Julius Caesar was assassinated nearby.

Spanish Steps, an ideal place for people-watching.

Via Condotti viewed from the Spanish Steps.

Column of Marcus Aurelius in the heart of the shopping district.

Piazza del Popolo, a large public space in the north of the city centre.

Piazza Navona, bustling with market stalls and tourists.

Palace of Justice on the western bank of the Tiber.

Basilica di Santa Maria Maggiore.

Castel Sant'Angelo, a mediaeval citadel and papal refuge.

St Peter's Basilica, viewed from atop the Castel Sant'Angelo.

St Peter's Basilica in the Vatican City, the head of Catholicism.

Statue of Pope Pius IX looks over St Peter's Square.

Interior of the enormous St Peter's Basilica.

Michelangelo's Pieta in St Peter's Basilica.

View across St Peter's Square, with crowds awaiting the Pope's election.

Ornate ceiling inside the Vatican Museums.

Raphael Rooms in the Vatican Museums.

Tomb of Pope John Paul II in the papal crypt below St Peter's Basilica.

View of Florence from across the River Arno.

Duomo, with its enormous dome designed by Michelangelo.

Ponte Vecchio, the most well known of the bridges across the River Arno.

Michelangelo's David in the Galleria dell'Accademia.

View of Palazzo Vecchio, framed by the Uffizi art gallery.

Door of the Battistero: The commissioning of its design began the Renaissance.

Palazzo Vecchio viewed from Piazza della Signoria.

Porcellino in Mercato Nuovo, whose snout is rubbed for good luck.

Statue of Dante outside Church of Santa Croce.

Statue of Petrarch outside the Uffizi gallery.

The Grand Canal, which cuts through the centre of Venice.

Bridge of Sighs, so named because it offered the final glimpse of the outside world for condemned men.

Ponte Rialto, the famous bridge crossing the Grand Canal.

Basilica di San Marco in St Mark's Square, obscured by heavy fog.

Island of San Giorgio Maggiore.

Tower of Pisa, which began to lean soon after the start of construction in 1173.

Duomo in the Field of Miracles, which also has a slight tilt.

Baptistery in the Field of Miracles, built in the 12th century.

View of Pisa from atop the Leaning Tower.

Buildings along the River Arno.

View of Naples from the shore.

Castel Sant'Elmo, which rises above the city of Naples.

Mt Vesuvius forms the backdrop behind the ruins of the Temple of Jupiter.

The ruins of Pompeii, with Mt Vesuvius lurking behind.

Much of Pompeii has been very well preserved.

Ruins at Ostia Antica, the harbour of Ancient Rome.

Roman road through Ostia Antica.

Amphitheatre, still used to stage performances in the warmer months.

Ostia Antica was already in decay by the 4th century AD.

The city was finally abandoned in the 9th century.