> There isn't much to do there if you aren't a fan of raw wilderness and extreme heat

Mostly this. If you want to see exotic animals, you'll be probably more comfortable on a Zoo. Favorite touristic points of Brazil seems to be northeast beach or coldest parts of the south. I was in vacation in Florianopolis, a capital city in the south, in 2019 and every time I said I was from the northeast they asked me: "and why are you wasting your vacation here?"

I imagine it would be interesting to learn about and get to know some of the tribal people.