An interesting place to visit near Curitiba (about 90 km) is Parque Estadual de Vila Velha. This is a State Park which offers some infrastructure to the visitor. There are two main guided tours in the park. One to see the rock formations and the other to see two caves more than 50 mts deep (called Furnas) and a beautiful lagoon (Lagoa Dourada). If you are in Curitiba, it’s definitely worth a visit!
The Goblet is the most famous rock formation in the park
Furnas formation – click on image to enlarge!