From the graceful French Quarter to the elegant Garden District, Louisiana's biggest city is unique in the USA. On a cool winter's day, New Orleans might seem as languid as the mighty Mississippi, but after dark it's the place America goes to let its hair down and turn the volume up. Visit in the next few weeks to find the city unusually quiet and intimate; Mardi Gras parades begin on January 19, augmented by the 47th Super Bowl football game on February 3.
Take a hike
Begin your French Quarter walk where New Orleans began: Jackson Square, originally the Place d'Armes – and modelled on the Place des Vosges in Paris. St Louis Cathedral is the oldest Catholic cathedral in the USA. Alongside, the Cabildo, built in 1795, was the original City Hall. Today, it's part of the Louisiana State Museum, open 10am to 4.30pm daily except Monday, $6 (£3.80).
The oldest structure in the Mississippi valley is north-east, along Chartres Street. The Ursuline Convent was built for a dozen nuns who came to spread Christianity through the new French colony; open 10am to 4pm daily except Sunday.
Zig and zag around the French Quarter's backstreets, to see the brick creole townhouses with their elaborate balconies, and the smaller Creole cottages whose steep, raked roofs reveal French Canadian origins. At 901 Bourbon Street, Café Lafitte in Exile (lafittes.com) says it's the oldest continuously operating gay bar in North America.
Along Dauphine and Burgundy Streets you find colourful homes away from the tourism melée. Cut south from here, past the Supreme Court Building, to St Louis Street – and lunch.
Lunch on the run
Try Johnny's Po Boys at number 511 and a half (johnnyspoboy.com). It's been selling the Po Boy – a baguette filled with anything from shrimp to eggs – since 1950. Their slogan: "Even my failures are edible."
For dessert, track down Café du Monde at 800 Decatur Street (cafedumonde.com) for a café au lait and a beignet (pronounced ben-yay) – a doughnut in icing sugar.
Take the free bus from the stop close to the Canal Street ferry on a 10-minute ride to Mardi Gras World (mardigrasworld.com; 9.30am to 4.30pm daily, $19.95/£12). Forty days before Easter is "Fat Tuesday", the last day before the austerity of Lent. In the frantic Lent build-up, there are dozens of parades with hundreds of lavishly decorated floats – many created in this massive warehouse on the Mississippi, from papier-mâché, paint and ingenuity.
Dining with the locals
The Acme Oyster House at 724 Iberville Street has served bivalves by the half dozen ($8.75/£5.50) for more than a century. For the main course, go around the corner to the sumptuous Palace Café, a former musical-instrument store at 605 Canal Street. Order seafood gumbo (£8/£5), with shrimp, okra and, yes, oysters. Round all that off at the Bourbon House at 144 Bourbon Street: try the chocolate pecan crunch ($8/£5).
Sunday morning: go to church
Tucked inside a courtyard at 828 North Rampart Street, the Voodoo Spiritual Temple (voodoospiritualtemple.org) celebrates the intoxicating essence of Africa mixed with French and Spanish influences, which combine to enhance life, death and everything in between.
Out to brunch
Galatoire's at 209 Bourbon Street has been flourishing for a century or more. The trout almandine – deep fried with roast almonds in a meunière sauce – is delicious, but oysters are also available.
Antoine's at 513 St Louis Street (antoines.com), offers its signature oysters Rockefeller ($7.50/£4.50) during the Sunday Jazz Brunch (11am to 2pm).
At Maskarade, 630 Saint Ann Street (frenchquartermaskstore.com) you can experiment with different identities. Close to the river, the French Market is a cheerfully touristy collection of stalls.
Take a ride
They used to have a streetcar named Desire (a city suburb), now there are three: along the river starting from a stop near the French Market; along Canal Street; and the main mobile attraction, the St Charles streetcar. Catch it from the stop on Canal Street and trundle towards the Garden District.
Walk in the park
The 19th-century bourgeoisie built their grand mansions in a separate city, Lafayette, a few miles south-west of the French Quarter — now known as the Garden District. For an expert eye on the most desirable residences, take a walk with New Orleans Historic Tours (tourneworleans.com; 11am and 1.45pm daily from 2727 Prytania Street. The $20 (£12.50) tour includes the strange tombs of Lafayette Cemetery No 1.
Icing on the cake
The Natchez, which is said to be "The last authentic steamboat on the river," sails from the quay every evening at 7pm on a Jazz Cruise ($41/£26) down Old Man River.