Despite the name suggesting it might be boring (looking at you, tourists who skip it), Jardim Botânico is actually pretty great. Around R$20-30 entry, massive grounds, and you can escape the beach crowds for a few hours.

Best part is the giant lily pads and the avenue of royal palms that looks like something from a movie set. Also has a decent café and clean bathrooms which is worth mentioning because... Well, it's Rio.

Go early morning or late afternoon to avoid the heat. Takes about 2-3 hours to see properly. Definitely not Jeff's idea originally but definitely worth the visit.