-The Serra Verde Express-

• The Serra Verde Express a train to the coastal town of Morretes, makes an excellent day trip and is for many tourists the main reason to visit Curitiba. The views from the train are unforgettable. The ride departs daily at 08:15 in the morning, descends through some of last remaining Atlantic rainforest and offers some spectacular views (not to mention it is one of the few train rides in Brazil). On Sundays the train continues to Paranaguá, although the last bit between Morretes and Paranaguá is not very scenic. There are three price levels of the tickets claiming to offer different levels of luxury: round-trip tickets are R$72 for economic class (hard to come by), R$92 for touristic (R$ 58 for kids), R$ 133 for the executive class (R$ 63 for kids) and R$290 for luxury class (R$ 205 for kids). Buy the cheapest ticket you can get since there really is not much difference between the cars. The return ticket is about 30% cheaper. In addition to the regular train, there's a special tourist train, the litorina, which only runs on weekends. One-way fare for the litorina is R$126. 
  
  
  

 One fun day trip is to leave the train in Morretes, and hitch a ride upstream by taxi or farmer's cart along the Nhundiaquara river. There is a bridge a few miles upstream (Porto de Cima) where you can rent an innertube (boiacross in Portuguese), and get a ride a few miles upstream on dirt roads. A fun float down the river through the tropical jungle is spectacular, refreshing, and you won't find a cleaner place in Brazil. An unforgettable day, especially if it is not a holiday time or weekend when it may be more crowded. Look for the bottle-hotel near the tube take-out point - that would be a memorable place to stay if it is open (seasonally)  (Info from Wikitravel )

Serra Verde Express OFFICIAL SITE