The church is the scene of the first act of Puccini's opera "Tosca", though opera fans will not find the Attavanti chapel, a poetic invention. The real church has much to recommend it - the recently restored facade shows the flamboyant Baroque style at its best. Inside, a golden light filters through high windows, showing off the gilded interior. Here lie the two popes of the Sienese Piccolomini family: on the left of the central nave is the tomb of Pius II, the first Humanist pope (reigned 1458-64); Pope Pius III lies opposite - he reigned for less than a month in 1503.

The church is famous for its beautiful dome, the largest in Rome after St. Peter's. It was built by Carlo Maderno in 1622-5 and was painted with splendid frescoes by Domenichino and Giovanni Lanfranco. The latter's extravagant style, to be seen in the dome fresco "Glory of Paradise", won him most of the commission, and the jealous Domenichino is said to have tried to kill his colleague. He failed, but Domenichino's jealousy was unnecessary, as shown by his two beautiful paintings of scenes from the life of St. Andrew around the apse and altar. In the Strozzi Chapel, built in the style of Michelangelo, the altar has copies of the "Leah" and "Rachel" by Michelangelo in San Pietro in Vincoli.

The remains of four temples were discovered here during rebuilding in the 1920s. Dating from the Republican era, they are among the oldest to have been found in Rome. They are known as A, B, C and D. The oldest (temple C) dates from the early 3rd century BC. It was placed on a high platform preceded by an altar and is typical of Italic temple plans as opposed to the Greek model.

Temple A is from later on in the 3rd century BC. In medieval times the small church of San Nicola de' Cesarini was built over its podium. The remains of its two apses are still visible. The north column stumps belonged to a great portico, the Hecatostylum (portico of 100 columns). In Imperial times two marble lavatories were built here - the remains of one are visible behind temple A. Behind temples B and C are remains of a great platform of tufa blocks. These have been identified as part of the Curia of Pompey, a rectangular building with a statue of Pompey, where the Senate met and Julius Caesar was murdered on 15 March 44 BC.

The delightful Fontana delle Tartarughe - "tartarughe" are tortoises - was commissioned by the Mattei family to decorate "their" piazza between 1581 and 1588.

The design was by Giacomo della Porta, but the fountain owes much of its grace and charm to the four slender bronze youths each resting one foot on the head of a dolphin, sculpted by Taddeo Landini. Nearly a century later an unknown sculptor was inspired to add the struggling tortoises to complete the composition.

Built in honour of Octavia (the sister of Augustus and the abandoned wife of Mark Antony), this is the only surviving portico of what used to be the monumental piazza of Circus Flaminius. The rectangular portico enclosed temples dedicated to Jupiter and Juno, decorated with bronze statues. The part we see today is the great central atrium originally covered by marble facings.

In the Middle Ages a great fish market and a church, Sant'Angelo in Peschiera, were built in the ruins of the portico. As the church was associated with the fishing activities on the nearby river port, aquatic flora and fauna feature in many of its inlays. Find the marble plaque on the facade: fish longer that this slab were given to the city's "conservatori" (governors).

The Ghetto

The first Jews came to Rome as traders in the 2nd century BC and there has been a Jewish community in Rome ever since. Jews were much appreciated for their financial and medical skills during the time of the Roman Empire.

Systematic persecution began in the 16th century. From 25 July 1556 all Rome's Jews were forced to live inside a high-walled enclosure erected on the orders of Pope Paul IV. The Ghetto was in a unhealthy part of Rome. Inhabitants were only allowed out during the day, and on Sundays they were driven into the Church of Sant'Angelo in Peschiera to listen to Christian sermons - a practice abolished only in 1848.

Persecution started again in 1943 with the German occupation. Although many Jews were helped to escape or hidden by Roman citizens, thousands were deported to German concentration camps. Today many Jews still live in the former Ghetto and the medieval streets, with shops selling typical Roman kosher food, retain much of their old character.

In 17th-century Rome the plague could still strike fiercely and there were no reliable, effective remedies. Many Romans simply prayed for a cure to a sacred medieval icon of the Virgin, the Madonna del Portico. When a particularly lethal outbreak of plague abated in 1656, popular gratitude was so strong that a new church was built to house the icon in appropriate splendour.

The church, designed by a pupil of Bernini, Carlo Rainaldi, was completed in 1667. The main elements of the lively Baroque facade are the graceful columns, symbolizing the supporters of the true faith.

Inside the church stands a fabulously ornate, gilded altar tabernacle with spiral columns which was designed by Giovanni Antonio de Rossi to contain the image of the Virgin. The side chapels are decorated by some of Rome's finest Baroque painters: Sebastiano Conca, Giovanni Battista Gaulli (known as Il Baciccia) and Luca Giordano.

This typical small square has kept its medieval atmosphere, even though its buildings were renovated in the 17th century. The remains of the 12th-century Torre dei Margani - one of the powerful Roman families of that time - gives a distinguishing mark to the piazza.

Also the five streets radiating from the piazza keep an organic character of ancient times.

The curved outer wall of this vast amphitheatre has supported generations of Roman buildings. It was built by the Emperor Augustus (27 BC - AD 14), who dedicated it to Marcellus, his nephew and son-in-law, who had died aged 19 in 23 BC.

The Middle Ages were a turbulent time of invasions and local conflicts and by the 13th century the theatre had been converted into the fortress of the Savelli family. In the 16th century Baldassarre Peruzzi built a great palace on the theatre ruins for the Orsini family, including a garden facing the Tiber. The lower arches were later occupied by humble dwellings and workshops.

Close to the theatre stand three beautiful Corinthian columns and a section of frieze. These are from the Temple of Apollo, which housed many great works of art that the Romans had plundered from Greece in the 2nd century BC.

This beautiful unadorned church was built in the 6th century on the site of the ancient city's food market. The elegant Romanesque bell tower and portico were added during the 12th century. In the 19th century a Baroque facade was removed and the church restored to its original simplicity. It contains many fine examples of Cosmati work, in particular the mosaic pavement, the raised choir, the bishop's throne and the canopy over the main altar.

Set into the wall of the portico is the Bocca della Verità (Mouth of Truth). This may have been a drain cover, dating back to before the 4th century BC. Medieval tradition had it that the formidable jaws would snap shut over the hand of those who told lies - a useful trick for testing the faithfulness of spouses.

These miraculously well-preserved Republican temples are particularly appealing by moonlight, in their grassy enclave under the umbrella pines beside the Tiber. They date from the 2nd century BC and were saved for posterity when they were reconsecrated as Christian churches in the Middle Ages. They offer rare examples of combined elements from Greek and Roman architecture.

The rectangular temple (formerly known as the Temple of Fortuna Virilis) was in fact dedicated to Portunus, the god of rivers and ports - a reference to the nearby port of ancient Rome. Set on a podium, it has four Ionic travertine colums fluted at the front and 12 half-columns, embedded in the tufa wall of the cella - the room that housed the image of the god. Nearby is the small circular Temple of Hercules. It is often referred to as the Temple of Vesta because of its similarity to the one in the Forum.

In the hollow of the street named after the Velabrum, the swamp where Romulus and Remus are said to have been found by the she-wolf, is a small church dedicated to St. George, whose bones lie under the altar.

The 7th-century basilica has suffered over the centuries from periodic floods, and in 1993 a bomb caused extensive damage to the front of the church. Careful restoration has however returned it to its original appearance.

A double row of assorted granite and marble columns (taken from ancient Roman temples) divide the triple nave. The austerity of the cool grey interior is relieved by golden frescoes in the apse (attributed to Pietro Cavallini, 1295). The facade and the bell tower date from the 12th century.

Arco di Giano

Probably dating from the reign of Constantine, this imposing four-facade marble arch stood at the bustling crossroads on the edge of the Forum Boarium, near the ancient docks, Merchants and customers did business in its shade. On the keystones above the four arches you can see small figures of the goddesses Roma, Juno, Ceres and Minerva. In medieval times the arch used to form the base of a tower fortress. It was restored to its original shape in 1827.

Cordonata

From Piazza Venezia, the Capitol is approached by a gently rising, subtly widening ramp - the Cordonata, designed by Michelangelo. At the foot is a pair of granite Egyptian lions. The top of the ramp is guarded by restored Classical statues of the Dioscuri, Castor and Pollux.

Piazza del Campidoglio

When Emperor Charles V visited Rome in 1536, Pope Paul III Farnese was so embarrassed by the muddy state of the Capitol that he asked Michelangelo to draw up plans for repaving the piazza, and for renovating the facades of the Palazzo dei Conservatori and Palazzo Senatorio.

Michelangelo proposed adding the Palazzo Nuovo to form a piazza in the shape of a trapezium, embellished with Classical sculptures chosen for their relevance to Rome. Building started in 1545 but progressed so slowly that Michelangelo only lived to oversee the double flight of steps at the entrance of Palazzo Senatorio.

The piazza was completed in the 17th century, the design remaining largely faithful to the original. Pilasters two storeys high and balustrades interspersed with statues link the buildings thematically. At the centre of the piazza stands a replica of a statue of Marcus Aurelius. The original is in the Palazzo Nuovo. Palazzo Nuovo and Palazzo dei Conservatori house the Capitoline Museums, with their fine collections of Classical sculpture and art galleries.

Basilica di Santa Maria D'Aracoeli

The Aracoeli staircase numbers 124 marble steps and was completed in 1348, some say in thanks for the passing of the Black Death, but probably in view of the 1350 Holy Year. The 14th-century tribune-turned-tyrant Cola di Rienzo used to harangue the masses from this staircase. In the 17th century foreigners used to sleep on the steps, until Prince Caffarelli, who lived on the hill, scared them off by rolling barrels filled with stones down them.

Dating from at least the 6th century, the church of Santa Maria in Aracoeli, or St. Mary of the Altar in the Sky, stands on the northern summit of the Capitoline, on the site of the ancient temple to Juno. The church of the Roman senators and people, this basilica has been used to celebrate many triumphs over adversity. Its ceiling, with naval motifs, commemorates the Battle of Lepant (1571), and was built under Pope Gregory XIII Boncompagni, whose family crest, the dragon, can be seen towards the altar end.

The church is most famous for an icon with apparently miraculous powers, the "Santo Bambino", a 15th-century olive-wood figure of the Christ child which was carved out of a tree from the garden of Gethsemane. Its powers are said to include resurrecting the dead, and it is sometimes summoned to the bedsides of the gravely ill. At Christmas the Christ Child takes its place in the centre of a picturesque crib, but is usually to be found in the sacristy.

Known as Il Vittoriano, this monument was begun in 1885 and inaugurated in 1925 in honour of Victor Emmanuel II of Savoy, the first king of a unified Italy. The king is depicted here in a gilt bronze equestrian statue, over-sized like the monument itself - the statue is 12 m (39 ft) long.

Built in austere white Brescian marble, the "wedding cake" or "typewriter" (two of many insulting nicknames given to this unloved white elephant) will never mellow into the ochre tones of surrounding buildings. It is widely held to be the epitome of self-important, insensitive architecture.

Its negative fame is now starting to change: the edifice contains an exhibition area offering important temporary exhibitions. To note that in June 2002, Il Vittoriano has been re-opened to the public, to become one of the most glorious "belvederes" over Rome's unique scenarios.

One of the first Renaissance civic buildings in Rome, the palazzo's arched windows and doors are so harmonious that the facade was once attributed to the great Humanis architect Leon Battista Alberti. It was more probably built by Giuliano da Maiano, who is known to have carved the fine doorway on to the piazza.
Palazzo Venezia was built in 1455-64 for the Venetian cardinal Pietro Barbo, who later became Pope Paul II. It was at times a papal residence, but it also served as the Venetian Embassy to Rome before passing into French hands in 1797. Since 1916 it has belonged to the state; in the Fascist era Mussolini used it as his headquarters and addressed crowds from the central balcony.

The interior is best seen by visiting the Museo del Palazzo Venezia. It holds a first-class exhibition of early Renaissance painting, and many other important collections. The building also hosts major temporary exhibitions.

Dating from between 1568 and 1584, the Gesù was the first Jesuit church to be built in Rome. Its design epitomizes Counter Reformation Baroque architecture and has been much imitated throughout the Catholic world.

The layout proclaims the church's two major functions: a large nave with side pulpits for preaching to great crowds, and a main altar as the centrepiece for the celebration of the mass. The illusionistic decoration in the nave and dome was added a century later. Its message is clear and confident: faithful, Catholic worshippers will be joyfully uplifted into the heavens, while Protestants and other heretics are flung into hell's fires.