Deep carving marking mainly the eastern border of the Park. It is an imposing gorge which has been dug during the last million of years by torrent Rio Freddo in the calcareous massif of Lias Inferiore.
Deep carving of the liassic limestone of Mt. Catria.
Imposing natural walls of the western slope of the Park, situated immediately above the village of Sigillo.
Characteristic white marly-calcareous formations outcropping from ancient detritus and cemented breccias.