The Serra Verde Express goes from Curitiba to the port of Paranaguá, criscrossing forests and the beautiful Serra do Mar making stops in quaint towns like Morretes and Antonina.
It's no Orient-Express but hey... it's better than no train at all! :)
Curitiba to Paranaguá, stopping at Túnel Roça Nova, Santuário do Cadeado and Estação Véu da Noiva.
Here's their top-of-the-line section: