Praia de Tambaba, 10km south of Jacumã, is famed as the only official nudist beach in the region. It's a beautiful place that warrants a visit on its own right even if you don't plan on getting naked. It's divided into two sections: closest to the car park is the regular clothing-required section with a short stretch of sand and jagged rock formations in the water but the nicest part is the larger clothing-free area which is backed by stunning cliffs.
The naturist part also has a broad swath of petrified sandstone forming natural tidal pools along the shoreline. Make sure to stop at the lookout point on the way down for spectacular views.
Men may only enter the nude section if they are gay couples, accompanied by a woman or have an official 'naturist' passport available from the local authorities. There are a couple of food vans in the main car park in addition to barracas down on the sand.
Tambaba hosts the one-of-a-kind Open de Surf Naturista (Nude Surfing Festival) in August.