The physical geography of the Abruzzi territory is characterised by a series of broad, orographically uniform areas. Moving from East to West, we first come upon the hilly area, after which the foothills, and finally, the mountains.
The hilly area is distinguished by low-elevation high grounds and by stretches of sub-level areas gently sloping toward the sea. This area takes its shape from Plio-Pleistocene marine deposits (clay, sand, and conglomerates).
In the foothills there are high grounds reaching up to 1000 metres above sea level; these are separated by deeply cut, steep-sloped valleys. Accelerated erosion processes have created peculiar formations near the steep clayey hillsides. These formations are particularly striking in the stretches of ravines found in the area between the low-lying course of the River Vomano and the River Fino, and they find their greatest expression in the “pits” at Atri. The ravine areas develop mainly along the hills, but they can also be found in the foothills (Pennapiedimonte, Guardiagrele, Roccamontepiano, Manoppello, Turrivalignani, Lettopalena, Lama dei Peligni, Civitella Messer Raimondo and Palombara).
The true mountain range is composed of high-elevation massifs forming a large block characterised by a series of high grounds in subparallel lineation, generally making the range quite recognizable. Three orographic areas can be distinguished: the first begins at the Adriatic Sea (Monti della Laga - Gran Sasso – Morrone - Maiella); there follows a middle area (Monti d’Ocre – Sirente - Monte Genzana – Monte Greco, which form the area to the East, and the group of Velino - Montagna Grande - Monte Marsicano, which form the more interior lineation); and, finally, a third area on the Tyrrhenian/Lazio side (Simbruini and Èrnici Mountains).