The Monte Penna Nature Reserve is found south-west of Monte Amiata, in the municipality of Castell'Azzara, and covers a thousand hectares of protected territory in a series of peaks of which Poggio della Vecchia (1086 metres) and Civitella (1107 metres) are the highest. It is a green area covered almost entirely with ash, beech and Turkey oak forests. The Bosco della Fonte on the Poggio della Vecchia is of great natural interest, while near to the town of Selvena you can find some chestnut trees that are quite enormous. The reserve is also home to many birds of prey, like owls and buzzards, but you can also spot foxes, porcupines, wild boar, deer, weasels, skunks and martens.
Finally, you can't miss a visit to the ancient ruins of Rocca Silvana.