Take a cemetery tour. There are several that target St. Louis Cemetery. I've been there many times and it's been the inspiration for a few of my books. I was once caught in a massive thunderstorm there and crawled inside one of the unsealed vaults. I can't say it was totally empty because it wasn't really. In New Orleans, after one year and one day, you can share the tomb with another family member. During the extremely hot, and humid summer's there, tombs will reach 300 or so degrees round the clock. When a body spends a full summer in the vault what is left is some rotting wood, bones and ashes. The wood is disposed of and the bones and ashes are brushed to the back of the tomb with a push broom where there is a space of a few inches. The remains drop to the bottom space under the vaults, and the vault is ready to receive the next body. It looked relatively remains free when I crawled in feet first, and whomever had rested there before me didn't seem to mind. I waited out the downpour for about ten minutes before this feeling that regardless, if a family member of someone showed up and saw me they'd probably get pissed; not to mention I was really being disrespectful without meaning too, and at the least inconsiderate. So with extreme guilt, I crawled out and sloshed my way back to my hotel. The soaking my penance.
Someone told me they stopped the tours for a little while, but some companies now do them again.
And as I have mentioned here a few times, a must stop is a visit to Praline Connection. Off the beaten path, but the BEST in my opinion.
The aquarium is very nice too.
I love NOLA. It's history is rich, and amazing. Before Katrina we nearly bought a winter home there.