The climb to the summit of Lonquimay, an active volcano, is a fantastic day hike. Curacautin is a good base for exploring the region but the climb to Lonquimay begins 30 km or so east on the road to Lonquimay, near a village called Malalcahuello. Form the town, a dirt road leads to Refugio Pewen (follow signs for Volcan Lonquimay), where you pay 5000 per person for access to the trailhead. It's a 3 hour hike up, and it's very tough going on the loose scree and volcanic ash.
Curacautin has a nice main square, which is a good place to relax wth a book on a hot day, beneath the shade of the trees. There isn't a whole lot to see in town, but most restaurants, hotels and amenities are close to the square.
The Salto de la Princessa is a a small waterfall, located 21 km east of Curacautin, on the road to Lonquimay. As with Salto del Indio, Salto de la Princessa is difficult to reach by public transport. A signposted turnoff leads across a bridge to a place where you can park, and the waterfall is a short walk away. You can also climb through the forest to the top of the waterfall though you need to be careful here as the paths are steep and you could easily fall a long way. Views from the top are excellent.
We ate in El Gato Negro on all 3 nights of our stay in Curacautin. The restaurant was basic, but the food was delicious and excellent value. I think we ate the same meal every night - 2 churrascos, a shared plate of chips and 2 litrres of Cristal beer. The churrascos were huge, biggest I've ever seen, while the shared plate of chips would have fed four people. For drinks there was only coke, beer or spirits, meaning we had to go with the beer!