I read Don Quixote and thought it might be fun to visit some parts of Spain mentioned in the books. Then after looking at some maps and seeing a stark lack of trees, I decided I wouldn't enjoy the trip.
The inner center and hot south can be more dusty and discouraging, but you can still be surprised by a few, not well known, jewels like Cabañeros, Valsain's pine forest, Alto Tajo, or Grazalema and the last relict Mediterranean -humid- forests in Cadiz. Plenty also of lagoons, marshes and aquatic ecosystems to visit, like Doñana or Daimiel. The biosphere reserve Hayedo de Montejo is located in Don Quixote's land.