What's the must-see thing in New Orleans?

Jackson Square has been the civic heart of New Orleans since 1721, when French colonial engineers laid it out as a military parade ground called Place d'Armes. St. Louis Cathedral, completed in its current form in 1794, fills the north side of the square. The white stucco facade and triple steeples catch the first light off the Mississippi every morning. Get there before 9am. The flagstone pavement is still cool enough to stand on, the brass bands haven't started competing for volume, and you can walk straight into the cathedral without a line. By 11am on a September morning, the wet heat closes in, shade from the Pontalba apartment buildings covers only the east and west flanks, and every stone surface you touch holds warmth. The Cabildo, the 1795 Spanish colonial building where the Louisiana Purchase transfer papers were signed in 1803, sits immediately left of the cathedral. It's now part of the Louisiana State Museum, with admission at $9 for adults. That single block, from cathedral to Cabildo, puts 300 years of the city's political and religious history into a 5-minute walk.

Saint Louis Cemetery No. 1, founded in 1789, sits 5 blocks northwest of Jackson Square on Basin Street at the edge of Tremé. The above-ground tombs look like a miniature stone city. Whitewashed plaster cracks in the subtropical heat. Iron gates have rusted to the color of dried blood. New Orleans buries above ground because the water table sits less than a meter below the surface. You can only enter with a licensed tour guide, a rule the Archdiocese of New Orleans imposed in 2015 after repeated vandalism. Tours cost around $25 and run 45 minutes to an hour. Book the morning slot. By afternoon the tombs radiate stored heat and there is zero shade anywhere inside. The narrow paths between the vaults smell like warm limestone and old rain. Worth noting, the cemetery closes at 3pm most days, and the last guided entry is typically around 2pm.

Congo Square sits inside Louis Armstrong Park, a 10-minute walk north from Jackson Square through Tremé. From the 1740s through the 1850s, enslaved Africans gathered here on Sundays to play drums, sing, and trade goods. The French Code Noir permitted these gatherings when later American law would not have. Those Sunday sessions are the direct origin of jazz, and of the second-line parade tradition you might still hear on weekends. The square itself is a brick-paved circle surrounded by sycamores. It is not much to look at. That said, stand there on a humid morning and you might hear a brass band rehearsing somewhere deeper in Tremé, the low thud of a tuba carrying over the rooftops. The park is free and open daily. Mind you, Louis Armstrong Park sits at the northern edge of the French Quarter in an area where solo-traveler safety rates 3.8 out of 10 (see the TTDI Solo-Safety Index). Stick to daylight visits on the main paths. After dark, take a rideshare.

If you have one morning in New Orleans, spend it on this 3-stop route. Start at Jackson Square by 8:30am, walk through the cathedral and the Cabildo by 10am, then head north through Tremé to Congo Square. Circle back down Basin Street to Saint Louis Cemetery No. 1 for a late-morning tour. The whole loop covers about 2 kilometers on flat ground. September heat is the main adversary. Today's temperature reached 32.3°C with a feels-like of 37.1°C by noon, and humidity sat at 62%. Carry water. Wear a hat. The brick and flagstone pavement throws heat upward, so your feet and face take the worst of it. Cotton tends to breathe better than synthetics in this kind of humidity. To be fair, the French Quarter is walkable in a way most American cities are not. Blocks are short, and nearly every corner has a cafe with air conditioning where you can cool down over a $4 iced coffee and a $3 beignet. Don't try to fit Frenchmen Street, the Garden District, and Magazine Street into the same day. Those deserve separate afternoons.