Hello,
in fact, Valdivia is not only a very nice place to visit, but it gives the name to one of our most typical and worldwide known Chilean landscapes, the "Valdivian rainforest", which was once spread all over the South of the country and today, although seriously diminished, reaches up to the Chiloé region. While extremely varied both in flora and fauna, its most characteristic species belong to the "Nothofagus" genus, the so called southern beeches.
There are some areas to the North of the land where such kind of forest can also be seen. As far as I know, the "Fray Jorge" National Park, roughly 300 km Northwest of Santiago, represents the northernmost patch of Valdivian rainforest. But if you want to know the real thing with all its rich biodiversity, Valdivia is certainly the right choice.