Pacentro lies in the Apennine Mountain Range on a plateau consisting of small hills 650 metres (2,133 ft) above sea level. The castle sits on one hill (Colle Castello) at one end of town and the other hill (Colle San Marco) is where the old Church of S. Marco used to sit. The town is just below Mount Morrone and just above the Peligna Valley (Conca Peligna) and the City of Sulmona. Pacentro is part of the
Majella National Park (Parco Nazionale della Majella) and is renowned for its springs and fresh mountain water that comes from the snow of the Majella.