The landscape of the park consists of a series of wild gorges that abruptly interrupt the continuity of the surrounding area of low pre-Apennine landscape and rolling hills. The protected area is thus interspersed with magnificent and spectacular hatitats susch as the Frasassi Gorge, the Della Rossa Gorge and valle Scappuccia. Their steep cliffs recount history that began in the Jurassic Period, around 210 milion years ago, when central Italy was still submerged beneath a sea that was an ideal environment for marine life, comparable with that of the present day Bahamas.
The accumulation of calcareous shells of microorganisms and lager species, as well as sediments transporter by the rivers, then gave rise to the great carbonate platform of Limestone massif, which emerges here in outcrops that are even more than five hundred metres in thickness.
This is constituted almost entirely by calcite minerals and has a very thick strata, between which strips of vegetatio rarely grow. In contrast to the spectacularly wild, vertical cliffs, the mountain peaks i the park rarely rech 1000 metres in height and can be easily climbed by road orfootpath. The rocks that emerge everywhere are extremely rich in fossils of every size. In 1976, durino excavations for the construction of a road tunnel, the remains were discovered of an ichthyosaurus, a sea reptile that lived one hundred and fifty years ago. It is now on display at the local museum in san Vittore Terme.
The rocky gorges werw formed bt tectonic phenomena, in addition to which there was the erosive action over time of two important water systems- the River Esino and its tributary, the River Sentino. In the area covered by the Park , both rivers flow along chasnnels that have cut deeply into the White Jurassic limestone, creating gorges and rapids that provide a particolar attraction for lovers of water sports.