Adults and kids with a fondness for reptiles will be in heaven at the Instituto Butantan (Av. Vital Brasil 1500, Butantã, tel. 11/3726-7222, www.butantan.gov.br , 9 a.m.–5 p.m. Tues.–Sun., R$5). The institute is one of the world’s foremost research centers of poisonous snakes and insects, with the aim of creating antivenin serums.
Located on the University of São Paulo’s sprawling campus, it is home to some 54,000 slithering creatures, ranging from common Brazilian anacondas and boa constrictors to exotic imports such as the Indian python, which can measure up to a spooky 6 meters (20 feet) in length.
There is also a colorful collection of iguanas, scorpions, frogs, and lethal spiders. Also on the premises is the Museu de Microbiologia, where you can gaze through microscopes at everything from fleas and fungi to human blood samples.
To get to Instituto Butantan, take the Metrô to Cidade Universitária and then a quick taxi ride (finding your way by foot is tricky).