well...first of all, August in NOLA is hot as hades, and as humid as a 14 year old boys armpits during puberty...so be aware that if you plan on doing a lot of outside walking or cycling you will be sweatier than your last trip to a health club sauna. that being said...
tons of things to see and do. Crime has been up a lot lately, so you may not want to do a lot of walking around off the beaten path in the FQ after dark. many a great restaurant, from Commander's Palace -typically one of the top 5 rated restaurants in the US annually and you need a jacket to think about entering - to hole in the wall BBQ and Pizza places, and everything in between. Do not eat at any restaurant that has a guy out front waving menus to get you inside, these are tourist traps and not good. some places to consider (in no certain order, and fancy to not as well, and all in downtown/FQ area or a short uber or streetcar ride away):
Commander's Palace
Galatoire's
pizza delicious
crescent city steaks
ruby slipper cafe
cafe du monde
cochon or cochon butcher
pesche
willa jean
parkway bakery (po-boys)
cafe maspero
dat dog
port of call
the joint (bbq)
french toast
Venezia's
Katie's mid-city
Liuzza's (cash only)
Angelo Brocato (for dessert)
Horn's Eatery
Elizabeth's
Bywater Bakery
Joey K's
Mahoney's po-boys
Atchafalaya
Clancy's
Shaya
Luke
Jacques-Imo's (near impossible to get in, but worth the effort)
Emeril's
Too hot for the zoo, too hot for a riverboat cruise take the Canal Street ferry for a quick trip across the river and back, has AC and only costs a few bucks, faster and better than a 3-hour river cruise which gets boring after 15 minutes), may be too hot for an airboat ride or swamp tour, aquarium is nice and AC. WW2 musuem is huge, covering multiple buildings, you won't be able to get through more than 1-2 in a day, but worth it (Higgins Hotel across the street is cool, and has a nice rooftop bar with a great view). Ride the streetcar. browse all the unique shops on magazine street. check out the jazz lounge at the ritz-carlton. a number of good micro-breweries if you like beer (Urban South, 2nd line are a couple of good ones). National Park service does free walking tours in FQ. ghost and vampire tours after dark. carriage rides are over-rated and most of what they tell you is fabricated. JAMNOLA is an interactive art experience.
this should give you a good start...
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