Some 40 kilometers (25 miles) northeast from Canela , straddling Rio Grande do Sul ’s frontier with Santa Catarina , lies the Parque Nacional de Aparados da Serra] (tel. 54/3251-1277, 9 a.m.–5 p.m. Wed.–Sun., R$6), a magnificent natural park that encompasses some 60 canyons as well as breathtaking waterfalls, lush subtropical vegetation, and one of the only remaining araucária forests in Brazil .
By far, the most dramatic highlight of the park is the 6-kilometer-long (4-mile-long) Cânion de Itaimbezinho, which plunges to vertiginous depths of 720 meters (2,360 feet) and boasts two waterfalls. From the visitors center at the main park entrance, 18 kilometers (11 miles) along the RS-429 from the town of Cambará do Sul, two trails allow you to explore the canyon. The easiest 30-minute path leads to the canyon’s rim. A second, more difficult route, descending into the canyon itself, requires a guide and trekking gear.
A more recent extension of the park’s area into Santa Catarina—known as the Parque Nacional da Serra Geral (tel. 54/3504-5389, 8 a.m.–6 p.m. daily, free)—features the gigantic Cânion da Fortaleza as well as the impressive Malacara and Churriado canyons. By car—a tricky 22-kilometer (14-mile) drive over the CS-012, a winding dirt road that is a continuation of Cambará do Sul’s main avenue—you can get to the park’s entrance, close to the edge of Cânion da Fortaleza.
From here, a 30-minute trail leads to a lookout point where, on clear days, you can see the Atlantic Ocean in the distance. From Fortaleza, visiting the other two canyons involves an eight-hour, 22-kilometer (14-mile) strenuous hike (there-and-back) through the forest for which a guide (and some physical preparation) is necessary.
The best time to visit the region is during the winter (although temperatures are chilly) when visibility is best due to the lack of mist, or in the spring (Oct.–Nov.) in order to see wild blossoms. The months of April, May, and September can be very rainy. Call Cambará do Sul’s tourist office or check its website (www.cambaraonline.com.br ) for weather conditions. It is prohibited to swim in the park’s river and waterfalls.
Although the visitors center at Parque Nacional da Serra Geral is equipped with a tourist office, maps, and a restaurant, there are no guides at either of the parks—to hire one, contact the Associação de Condutores Locais de Eco-Turismo (Acontur) (tel. 54/3251-1320), whose headquarters is in Cambará do Sul’s Centro Cultural.
Since there is no bus service, if you don’t have a car, getting to the Parque Nacional de Aparados da Serra or Parque da Serra Geral requires hiring a taxi (tel. 54/3251-1320) or minivan to take you to the entrances and pick you up again. Canyon Turismo (Av. Getúlio Vargas 1098, tel. 54/3251-1027, www.canyonturismo.com ) offers a wide array of hiking and horseback excursions (lasting from half a day to three days) as well as rappelling and quadricycle outings. Several tour companies based in Gramado  and Canela  also offer full-day excursions to the parks.
Getting to Cambará by bus is not that easy. From Porto Alegre , 193 kilometers (120 miles) away, Citral (tel. 51/3228-5128, www.citral.tur.br ) has one daily bus that departs at 6 a.m. and takes five hours—due to numerous stops—to get to Cambará’s rodoviária (Rua Dona Úrsula 840, tel. 54/3251-1567). Otherwise, from Porto Alegre—as well as from Gramado and Canela—you have to go to the town of São Francisco da Paula, 60 kilometers (37 miles) from Cambará, and change buses from there.
If you’re driving from Porto Alegre, take the BR-166 to Taquara and then follow the RS-020, straight north. Beware that many of the roads around Cambará are not paved and can be particularly difficult to navigate when it rains.