By Bus

Before plunging into sightseeing on your own, you may like to take the most popular get-acquainted tour in Paris: Cityrama, 2 rue des Pyramides, 1er (tel. 01-44-55-61-00; Métro: Palais-Royal-Musée du Louvre). On a double-decker bus with enough windows for Versailles, you take a 2-hour ride through the city. You don't go inside any attractions, but you get a look at the outside of Notre-Dame and the Eiffel Tower, among other sites, and it helps you get a feel for the city. There's commentary in eight languages on earphones. Tours depart daily at 10am, 11am, and 2:30pm. A 1 1/2-hour orientation tour is 18€ ($23) adults, 8.50€ ($11) children. A morning tour with interior visits to the Louvre costs 39€ ($51). Half-day tours to Versailles (59€/$77) and Chartres (55€/$72) are a good value and relieve some of the hassle associated with visiting those monuments. A joint ticket that includes Versailles and Chartres costs 95€ ($124). A tour of the nighttime illuminations leaves daily at 10pm in summer, 7pm in winter, and costs 22€ ($29); it tends to be tame and touristy.

The RATP (tel. 08-92-68-77-14), which runs regular public transportation, also operates the Balabus, a fleet of orange-and-white big-windowed motor coaches. The only drawback is their limited operating times: Sunday and national holidays from 12:30 to 8:30pm, from April to the end of September. Itineraries run in both directions between Gare de Lyon and the Grand Arche de La Défense. Three Métro tickets will carry you along the entire route. You'll recognize the bus, and the route it follows, by the Bb symbol on its side and on signs posted along its route.

Friday Night "Rando" Fever

The Paris Roller Rando takes over the city on Friday nights, "rando" being short for randonnée, meaning tour or excursion. The starting time is around 10pm at the place d'Italie (also the name of the Métro stop). Roller folk from Paris and throughout Ile de France amass here to begin their 3-hour weekly journey through the city on rollerblades. Every Friday three motorcycle policemen lead the way with dome lights flashing, signaling moving cars to get out of the way. First-aid wagons follow the "rollers." On an average night in Paris, some 20,000 rollers show up. Many visitors like to stay up late that night to watch these "mad, mad Parisians" in all their crazed "rollermania."

Cruises on the Seine

A boat tour on the Seine provides vistas of the riverbanks and some of the best views of Notre-Dame. Many boats have sun decks, bars, and restaurants. Bateaux-Mouche (tel. 01-40-76-99-99; Métro: Alma-Marceau) cruises depart from the Right Bank of the Seine, adjacent to pont de l'Alma, and last about 75 minutes. Tours leave daily at 20- to 30-minute intervals from 10am to 11pm between April and September. Between October and March, there are at least five departures daily between 11am and 9pm, with a schedule that changes according to demand and the weather. Fares are 8€ ($10) for adults and 4€ ($5.20) for children 4 to 13. Dinner cruises depart daily at 8:30pm, last 2 hours, and cost 95€ to 125€ ($124-$163). On dinner cruises, jackets and ties are required for men.

Some people enjoy excursions on the Seine and its canals. The 3-hour Seine et le Canal St-Martin tour, offered by Paris Canal (tel. 01-42-40-96-97), requires reservations. The tour begins at 9:30am on the quays in front of the Musée d'Orsay (Métro: Solférino) and at 2:30pm in front of the Cité des Sciences et de l'Industrie at Parc de la Villette (Métro: Porte de la Villette). Excursions negotiate the waterways of Paris, including the Seine, an underground tunnel below place de la Bastille, and the Canal St-Martin. Tours are offered twice daily from mid-March to mid-November; the rest of the year, on Sunday only. As you glide along the waterways, recorded commentary in French and English relates how building supplies and food staples were hauled, with relative efficiency, into central Paris during the capital's building boom in the Napoleonic age of the 19th century. The cost is 17€ ($22) for adults, 14€ ($18) for seniors over 60 and students ages 12 to 25, 10€ ($13) ages 4 to 11, and free for children under 4.

Bike Tours

Some of the best-orchestrated bike tours in Paris are conducted in English and offered by Fat Tire Bike Tours (tel. 01-56-58-10-54); they depart from a spot that's immediately adjacent to the south leg (pilier sud) of the Eiffel Tower. (Look for a large yellow sign advertising the tours.) Between mid-February and mid-December, bike tours depart daily at 11am, and between May and September, an additional tour is offered at 3:30pm. Between April and October, an additional tour is offered at night, departing at 7pm from the same spot. The cost of any tour includes use of a bike and a protective helmet. Hint: If you're interested in participating in one of these bike tours, we recommend that you schedule your ascent to the upper levels of the Eiffel Tower for either immediately before or after your bike tour and that you arrive in clothing appropriate for a two-wheeled, self-propelled jaunt through the monumental avenues of central Paris. The cost is 24€ ($31) per person for the day tour and 28€ ($36) for the night tour. The night tour is more festive than the day tour and includes a complimentary ride aboard the bateaux mouches, the big-windowed panoramic boats that chug along the Seine beneath some of the most famous bridges in Europe.

Other Tours

The first audio-guided tours of Paris have been launched by Audio Visit, which takes you through such famous neighborhoods as the Champs-Elysées district, Louvre/Opéra, and Montmartre. English commentaries are available, costing 8€ ($10) per half-day or 15€ ($20) for both audioguide and bike during the same time frame. Rentals of the audioguide are available at the Syndicat d'Initiative de Montmartre, 21 place du Tertre, 18e; Paris Story, 11 bis, rue Scribe, 9e; and Maison Roue Libre, Forum de Halles, 1 Passage Montdétour, 1er. For more information, call tel. 04-78-29-60-72, or visit the Audiovisit website.

Context:Paris (tel. 888/467-1986 in the U.S., or 06-13-09-67-11) is an organization of graduate students and art-history professors who lead thematic walking tours of the city. Tours range from 1-hour orientation "chats" to 4-hour in-depth visits of the Louvre. Being academics, the guides try to create a college seminar feeling without being too obtuse and scholarly. Context:Paris also rents cellphones, arranges transportation, and organizes culinary excursions. Prices vary widely depending on what itinerary you select, but many tours cost 50€ to 60€ ($65-$78) per person.

Cracking the "Da Vinci Code"

When thousands of visitors carrying dog-eared copies of Dan Brown's The Da Vinci Code started pouring into the Louvre asking questions raised by the best-selling novel, tour guides caught on quickly. Today, Paris bustles with organized tours of fans wanting to explore the book's locations, such as the Louvre and St-Sulpice. With the film version, starring Tom Hanks, seen around the world in theaters and on DVD, interest in The Da Vinci Code shows no sign of waning.

The plot kicks off with the murder of the fictional Louvre curator, Jacques Saunière, in the museum's Grand Gallery. The church of St-Sulpice was home to the brass meridian marker and stone obelisk that play a key role in the novel's search for the Holy Grail.

Be warned that the Mona Lisa at the Louvre does not hang in the place as described by Brown in his blockbuster. And at St-Sulpice, Father Paul Roumanet has put up a sign for the thousands of fans streaming into the church in search of clues. "Contrary to fanciful allegations in a recent best-selling novel, this is not a vestige of a pagan temple," the sign reads. It also specifies that the initials "P" and "S" featured on circular windows refer to Saint Peter and Saint Sulpice -- not to the imaginary Priory of Sion, the secret society that is charged with protecting the Holy Grail in the novel. Roumanet fears that readers of Dan Brown's novel don't take it for fiction but "take it as established truth -- and that is not at all the case."

Lovers of the novel are booking the following tours to visit actual locations for the mega-hit that has sold millions of copies.

Paris Muse offers you both a private museum tour of the Louvre, exploring the themes of the book, or else a group walking tour of the book-related locales in Paris (tel. 06-73-77-33-52 in France). The 2-hour private tour costs 110€ ($143) for individuals or 90€ ($117) per person for parties of two or more. A less expensive walking tour takes place on Friday at 10:30am and 1pm, lasting 2 hours and costing 30€ ($39) per person. The meeting point for this tour is 23 Place Vendôme, 1er. More detailed information about meeting your guide will be sent when you reserve by e-mail.

Another walking tour lasts 2 hours and costs 25€ ($33) per person, and it's operated by Viator Tours (contact the outfit by searching the Viator website). Participants meet in front of the Ritz Hotel at Place Vendôme. For both tours above, take the Métro to Tuileries.