1. The first Mardi Gras celebration in New Orleans was held in the 1800s 2. Masks are mandatory on New Orleans Mardi Gras floats 3. Pirate Jean Lafitte helped defend New Orleans from the British 4. Preservation Hall is the oldest New Orleans jazz club 5. Hurricane Katrina was the US' costliest natural disaster 6. A haunted mansion sits in the French Quarter 7. New Orleans is nicknamed Crescent City 8. New Orleans features many above ground tombs 9. New Orleans was the Louisiana state capital before Baton Rouge 10. St. Louis Cathedral is the US' oldest active Roman Catholic church 11. Orleans Parish is the third-most-populous in Louisiana 12. 25% of the United States' fish species live in the Mississippi River 13. New Orleans was the largest Confederate city during the Civil War 14. City Park was originally used for dueling 15. Bourbon Street isn't named after the alcohol 16. The Lake Pontchartrain Causeway is the world's longest bridge 17. Dental floss was invented in New Orleans by Levi Spear Parmly 18. You can see the tomb of Voodoo Queen Marie Laveau in NOLA 19. The first recorded US Mafia activity happened in New Orleans 20. Canal Street is one of America's widest roads https://www.destguides.com/united-states/louisiana/new-orleans/fun-facts-new-orleans