Start: Palazzo del Quirinale

Finish: Piazza Santi Apostoli

Time: 3 1/2 hours

Best Times: Sunday mornings

Worst Times: Morning and afternoon rush hours on weekdays

This walking tour will lead you down narrow, sometimes traffic-clogged streets that have witnessed more commerce and religious fervor than any other neighborhood in Rome. Be prepared for glittering and very unusual shops that lie cheek by jowl with churches dating back to A.D. 500.

Begin in the monumental, pink-toned:

1. Piazza del Quirinale

Crowning the highest of the seven ancient hills of Rome, this is where Augustus's Temple of the Sun once stood (the steep marble steps that now lead to Santa Maria d'Aracoeli on the Capitoline Hill once serviced this spot), and part of the fountains in the piazza were built from the great Baths of Constantine, which also stood nearby. The palace, today home to the president of Italy, is open to the public only on Sunday mornings.

You can admire a nice view of Rome from the piazza's terrace, and then meander along the curiously lifeless streets that surround it before beginning your westward descent along Via della Dataria and your northerly descent along Via San Vincenzo to one of the most famous waterworks in the world, the:

2. Trevi Fountain

Supplied by water from the Acqua Vergine aqueduct, and a triumph of the baroque style, it was based on the design of Nicolo Salvi (who is said to have died of illness contracted during his supervision of the project) and completed in 1762. On the southwestern corner of the fountain's piazza you'll see a somber, not particularly spectacular church (Chiesa SS. Vincenzo e Anastasio) with a strange claim to fame: In it are contained the hearts and intestines of several centuries' worth of popes. This was the parish church of the popes when they resided at the Quirinal Palace on the hill above, and for many years each pontiff willed those parts of his body to the church. According to legend, the church was built on the site of a spring that burst from the earth after the beheading of St. Paul at one of three sites where his head is said to have bounced off the ground.

Throw a coin or two into the fountain to ensure your return to Rome, and then walk around to the right of the fountain along streets whose names will include Via di Stamperia, Via del Tritone, and Via F. Crispi. These lead to a charming street, Via Gregoriana, whose relatively calm borders and quiet apartments flank a narrow street that inclines upward to one of the most spectacular public squares in Italy:

3. Piazza della Trinità dei Monti

Partly because of its position at the top of the Spanish Steps (which you'll descend in a moment), partly because of its soaring Egyptian obelisk, and partly because of its lavish and perfect baroque symmetry, this is one of the most theatrical piazzas in Italy. Flanking the piazza are buildings that have played a pivotal role in French (yes, French) politics for centuries, including the Church of Trinità dei Monti, begun by the French monarch Louis XII in 1502 and restored during Napoleon's occupation of Rome in the early 1800s. The eastern edge of the square, adjacent to Via Gregoriana, is the site of the 16th-century Palazzetto Zuccaro, built for the mannerist painter Federico Zuccaro, with doorways and window openings fashioned into deliberately grotesque shapes inspired by the mouths of sea monsters. (It lies between Via Gregoriana, Via Sistina, and Piazza Trinità dei Monti.) In this building, at the dawn of the French Revolution, Jacques-Louis David painted the most politicized canvas in the history of France, The Oath of the Horatii (1784), which became a symbol of the Enlightenment then sweeping through the salons of Paris. Today the palazzetto is owned by the German Institute for Art History.

Begin descending the most famous staircase in the world, the:

4. Spanish Steps

This azalea-flanked triumph of landscape design takes its name from the Spanish Embassy, which was in a nearby palace during the 19th century. The Spanish, however, had nothing to do with the construction of the steps. Designed by Italian architect Francesco de Sanctis between 1723 and 1725, they were funded almost entirely by the French as a preface to the above-mentioned French church, Trinità dei Monti.

The Spanish Steps are at their best in spring, when they're filled with flowers that seem to cascade down into Piazza di Spagna, a piazza designed like two interconnected triangles. Curiously, in the early 19th century, the steps were famous for the sleek young men and women who lined the travertine steps, flexing muscles and exposing ankles in hopes of attracting an artist and being hired as a model.

The boat-shape Barcaccia fountain, in the piazza at the foot of the steps, was designed by Bernini's father at the end of the 16th century.

There are two nearly identical houses at the foot of the steps on either side. One is the home of Babington's Tea Rooms (see "Take a Break"); the other is the house where the English romantic poet John Keats lived -- and died. That building, at 26 Piazza di Spagna, contains the:

5. Keats-Shelley House

Keats died here on February 23, 1821, at the age of 25, during a trip he made to Rome to improve his failing health. Since 1909, when well-intentioned English and American aficionados of English literature bought the building, it has been a working library established in honor of Keats as well as Shelley, who drowned off the coast of Viareggio with a copy of Keats's work in his pocket. Mementos inside range from the kitschy to the immortal and are almost relentlessly laden with literary nostalgia.

6. Take a Break

Babington's Tea Rooms, Piazza di Spagna 23 (tel. 06-6786027; www.babingtons.com), has been serving homemade scones and muffins, along with a good cuppa, ever since it opened in 1893 by Miss Anna Maria Babington, using her original recipes. Celebrities and thousands of visitors have stopped off here to rest in premises inspired by England's Victorian age. Prices are high, however.

In the past, the Piazza di Spagna area was a favorite of English lords, who rented palaces hereabout and parked their coaches on the street. Americans now dominate the scene, especially since the main office of American Express is right on Piazza di Spagna and dispenses all those letters (and money) from home. Much to the dismay of many Romans, the piazza is also home to a McDonald's; however, it's not your average Golden Arches -- we've never seen one so lavish, and it's a good place to duck in if you need a restroom.

To the extreme southern edge of the square -- flanked by Via Due Macelli, Via Propaganda, and Piazza di Spagna -- is an odd vestige of the Catholic church's sense of missionary zeal, the:

7. Collegio di Propoganda Fide

Established in 1627 as the headquarters of a religious organization devoted to the training of young missionaries, this later became one of the most important centers for missionary work in the world. Owned and administered by the Vatican, it is therefore exempt from most of the laws and legalities of Italy. It contains design elements by two of the 17th century's most bitter artistic rivals, Bernini and Borromini.

The street that runs east-west as the logical continuation of the descent of the Spanish Steps is one of the most celebrated for style and fashion in Italy:

8. Via Condotti

It's lined with windows displaying the latest offerings from the Italian fashion industry. Even the least materialistic will enjoy window-shopping along this impressive lineup of the most famous names in international design. (Via Condotti is only the most visible of several upscale shopping streets in the neighborhood. For more of the same temptations, detour onto a smaller but equally glamorous parallel street, Via della Croce, 2 blocks to the north, and wander at will with your platinum card in hand. You'll need to return to Via Condotti eventually for the continuation of this walking tour.)

Via Condotti ends at a shop-lined plaza, Largo Goldoni, where your path will fork slightly to the right onto Via Tomacelli. Staying on the right (northern) edge of the street, turn right at the second intersection into Piazza Augusto, site of the:

9. Augustus Mausoleum

Once covered with marble and cypress trees, this tomb housed the ashes of many of the emperors of the 1st century all the way up to Hadrian (who built what is now Castel Sant'Angelo across the river for his own tomb). The imperial remains stayed intact within this building until the 5th century, when invading barbarians smashed the bronze gates and stole the golden urns, probably emptying the ashes onto the ground outside. The tomb was restored by Mussolini, and although you cannot enter the mausoleum itself, you can walk around it.

At the mausoleum's southwestern corner (Largo San Rocco), veer northwest until you reach the edge of the Tiber, stopping for a view of a bizarre, almost surreal compendium of ancient archaeological remnants restored and, in some cases, enhanced by Mussolini. It sits in an airy glass-and-concrete building beside the eastern banks of the Tiber at Ponte Cavour. Inside is one of the treasures of antiquity, the:

10. Altar of Peace (Ara Pacis)

The altar was built by the Senate as a tribute to Augustus and the peace he had brought to the Roman world. Look closely at the marble walls for portraits of Augustus's imperial family. Mussolini collected the few fragments of this monument that were scattered in museums throughout the world and gave his archaeological engineers a deadline for digging out the bulk of the altar, which remained underground -- below the water table and forming part of the foundation of a Renaissance palace on the Corso. Fearful of failing Il Duce, the engineers hit on the idea of chemically freezing the water surrounding the altar and simply chipping the relic out in huge chunks of ice, building new supports for the palace overhead as they went.

Proceed southward along Via Ripetta, cross over Piazza di Porto di Ripetta, and then fork left, walking southeast along Via Borghese for a block until you reach the austere entrance to the:

11. Borghese Palace (Palazzo Borghese)

Although many of the art treasures that once graced its interior now form part of the Galleria Borghese collections, this huge and somewhat disjointed palazzo retains its status as the modern-day Borghese family's seat of power and prestige. Bought from another family in 1605 by the cardinal who later became Pope Paul V, it was later occupied by Pauline Borghese, Napoleon's scandalous sister, a noted enemy of opera composer Rossini. Regrettably, the palace, carefully preserving its status as one of the most prestigious private homes in the world, is not open to the public.

From your vantage point, walk in a westerly direction along Via Fontanella Borghese back to a square you've already visited, Largo Goldoni, the western terminus of Via Condotti. The busy avenue on your right is one of the most richly stocked treasure-troves of Italian merchandise in Rome:

12. Via del Corso

When compared with the many meandering streets with which it merges, the rigidly straight lines of Via del Corso are unusual. In the 18th century, residents of Rome commandeered the street to race everything from horses to street urchins, festooning the windows of buildings on either side of the narrow street with banners and flags. Although today its merchandise is not as chic (or as expensive) as what you'll find along Via Condotti, it's well worth a browse to see what's up in the world of Italian fashion.

Walk south along Via del Corso's western edge, turning right (west) after 1 block into Piazza San Lorenzo in Lucina. The severely massive building on the piazza's northern edge is the:

13. Palazzo Ruspoli

This is a 16th-century testament to the wealth of the Florentine Rucellai family. Family members commissioned the same architect (Bartolommeo Ammannati) who designed parts of the Pitti Palace in Florence to build their Roman headquarters. Today the building belongs to a private foundation, although it's occasionally open for temporary, infrequently scheduled exhibitions. The entrance is at Via del Corso 418A, although your best vantage point will be from Piazza San Lorenzo in Lucina.

On the piazza's southern edge rises the:

14. Chiesa di San Lorenzo in Lucina

Most of what you'll see today was rebuilt around 1650, although if you look carefully, the portico and most of the bell tower have survived almost unchanged since the 1100s. According to tradition, this church was built on the site of the mansion of Lucina, a prosperous Roman matron who salvaged the corpses of Christian martyrs from prisons and amphitheaters for proper burials. The church was founded by Sixtus III, who reigned for 8 years beginning in A.D. 432. Inside, look for the tomb of the French painter Poussin (1594-1665), which was carved and consecrated on orders of the French statesman Chateaubriand in 1830.

After your visit, retrace your steps back to Via del Corso and walk southward until you reach the venerable perimeter of:

15. Piazza Colonna

Its centerpiece is one of the most dramatic obelisks in town, the Column of Marcus Aurelius, a hollow bronze column rising 25m (83 ft.) above the piazza. Built between A.D. 180 and 196, and restored (some say "defaced") in 1589 by a pope who replaced the statue of the Roman warrior on top with a statue of St. Paul, it's one of the ancient world's best examples of heroic bas-relief and one of the most memorable sights of Rome. Beside the piazza's northern edge rises the Palazzo Chigi, official residence of the Italian prime minister.

Continue walking west from Piazza Colonna into another square a few steps to the east, and you'll find yourself in a dramatic piazza designed by Bernini:

16. Piazza di Montecitorio

This was the site during ancient times of the cremations of the Roman emperors. In 1792, the massive obelisk of Psammetichus II, originally erected in Egypt in the 6th century B.C., was placed here as the piazza's centerpiece. Brought to Rome by barge from Heliopolis in 10 B.C., it was unearthed from a pile of rubble in 1748 at a site close to the Church of San Lorenzo in Lucina. The Palazzo di Montecitorio, which rises from the piazza's northern edge, is the modern-day site of the Italian legislature (the Chamber of Deputies) and is closed to the public.

Retrace your steps back to Via del Corso, and then walk south, this time along its eastern edge. Within 6 blocks, just after crossing over Via dell'Umilità, you'll see the solid stone walls of the namesake church of this famous shopping boulevard:

17. Chiesa San Marcello al Corso

Originally founded in the 4th century and rebuilt in 1519 after a disastrous fire, it was ornamented in the late 1600s with a baroque facade by Carlo Fontana. A handful of ecclesiastical potentates from the 16th and 17th centuries, many resting in intricately carved sarcophagi, are contained inside.

After your visit, return to the piazza in front of the church, and then continue walking for half a block south along Via del Corso. Turn left (eastward) onto Via SS. Apostoli, then turn right onto Piazza SS. Apostoli, and conclude this tour with a visit to a site that has witnessed the tears of the penitent since the collapse of the Roman empire, the:

18. Chiesa SS. Apostoli

Because of alterations to the site, especially a not-very-harmonious rebuilding that began in the early 1700s, there's very little to suggest the ancient origins of this church of the Holy Apostles. Pope Pelagius founded it in the dim, early days of the Roman papacy, sometime between A.D. 556 and 561, as a thanksgiving offering for the short-term defeat of the Goths at a battle near Rome. The most interesting parts of this ancient site are the fluted stone columns at the end of the south aisle, in the Cappella del Crocifisso; the building's front portico, added in the 1300s, which managed to incorporate a frieze from ancient Rome; and one of the first works executed by Canova, a painting near the high altar completed in 1787 shortly after his arrival in Rome. The church is open daily from 6:30am to noon and 4 to 7pm.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.