This route, accessible from the Gavorrano’s Gateway to the Park,  is a SIR / SIC (Regional and European site fo Interest) no. 108 Monts d’Alma, is a sort of open-air museum, which runs on the slopes and on top of the relief (m. 467 – Monte Calvo) overlooking Gavorrano. The area of Monte Calvo is a geotsite and a habitat of extraordinary interest, being an outcrops of Mesozoic limestone series Tuscan, with obvious phenomena of karst (sinkhole, caves, fractures) alternate with spots, scrubland and dry meadows that in spring are colored by spectacular blooms, especially orchids. The habitat is especially beneficial for small animals, especially reptiles, also unusual, as the Cervone, the Coluber Riccioli and Hermann’s tortoise. The meadows in spring and summer are filled with colorful butterflies and countless other invertebrates. Looking up you can see the imposing silhouettes of prey such as buzzards (Buteo buteo) and especially the Biancone (Short-toed Snake-Eagle – Circaetus gallicus ), circling in search of prey. Among mammals, in addition to the typical fauna of the Maremma hills (Wild boar, roe deer, porcupine, fox, etc.), In recent years has made its appearance even the wolf (Canis lupus). In the presence of outcrops of limestone red ammonite, with a little ‘luck, you can see parts of fossil ammonites of the Jurassic.