The findings and remains of antique buildings and settlements which are widespread throughout the whole park, are proof that this area was more or less intensely inhabited in Etruscan and Roman times. It also testifies that the exploitation of its underground resources, copper mines and ornamental stones probably began a few centuries before the Christian era.
From a geological point of view, the area is characterised by a ridge of structural origin, which follows the Apennine pattern and is characterised by formations of flysh from Montaione, limestone, gabbros and serpentines. The most ancient formation may be found in the so-called argillaceous shales of Iano and the Penere which date back to the Carboniferous age, in other words to over 250 million years ago.
On the side overlooking the Elsa Valley, the area between the river deposits at the bottom of the valley and the first stone like outcrops which are located more or less at the height of the two towns, consists in Pliocenic layers of clay and by a wide band, just a fraction higher, consisting mainly of sands and conglomerates. These are present mainly at higher levels.
In some areas of the mountainside overlooking Volterra, towards the Era river, a distinct change can be noticed between the clayey area and the stone-like structure. In these areas, which are also characterised by abrupt changes in the gradients, it is generally possible to notice a distinct boundary between the sowable areas of land, the typical crops of the rolling clayey hills and the woodland areas, which almost completely cover the hilltop area in which the most ancient types of stone appear.
The sandy belt which looks towards the Elsa river is characterised by its significant predominance of olive groves and vineyards, interspersed with cultivated strips of land and by the remains of woodland in the steeper areas and in the remaining woody areas in the valley lines. In this zone, the only pieces of land with bare soil and bushy pastures are more or less limited to the area of S. Stefano.
The side overlooking the Elsa Valley has a landscape which is often used as a symbol for the whole of Tuscany, with the isolated farmhouse, rows of cypress trees and vineyards being symbols which have always been used to a great extent to convey images of the region.