Castelvecchio Nature Reserve is situated in Val d’Elsa, a few kilometers westwards from San Gimignano.The Castelvecchio castle was an important fort during the medieval period. It had the advantage of a natural line of defence provided by two small rivers, the Botro di Castelvecchio and the Botro della Libaia, both tributaries of the larger river Elsa.
The particular landform of the Reserve and its consistently chalky topsoil influenced the heterogeneous vegetation. A multi-species oak wood covers a large area of the Reserve, particularly on the more gentle slopes. On the steeper, rocky outcrops however the ground is covered with stunning Mediterranean scrub such as colourful flowering heather, a plant which is commonly found on chalky land near the coast but which is much rarer in the inland.
Very little sun reaches the bottom of the narrow ravines of the Botro della Libaia and the Botro di Castelvecchio rivers causing an interesting thermic inversion. This has lead to the growth at the valley bottom of beech, maple and other rare tree species like the yew, that is a residue of the vegetation of millions of years ago, which are usually found much higher altitudes where the air is cooler.
The many rocky outcrops, often with over-hanging rock faces, are particularly concentrated in the southern part of the Reserve. These distinct formations lead to an interesting ambient variety that influences in a very important way the fauna. In fact, the rocky slopes that hold the ruins of the Castelvecchio castle provide a winter home to the exceptionally rare peregrine falcon. The limestone rocks are also the perfect habitat for the Solatopupa Juliana, a kind of mollusc found only in the rocky areas of Tuscany, western Liguria and Alto Lazio.
Several old abandoned farmhouses testify to the fact that the flatter areas of these limestone hills used to be cultivated. Today, this area is covered with dense shrubs and pastures. Along with the agricultural land that surrounds the park, these provide food for the many birds who live in the Reserve. For example, there is the rare short toed eagle which feeds almost exclusively on snakes, the red-backed shrike, the african stonechat and the redstart: three passeriformes which are under threat due to the increased use of intensive agricultural techniques.