 Pietraroja has a surface for agricultural use of 1797.99 hectares (as of 2000)

Its name probably derives from the Latin "petra robia "("red cliff") or from the Spanish equivalent "piedra roja "or French "pierre rouge ", due to the presence of some limestone of this colour on the oriental side of the Mutria, that overhangs it.At Pietraroja there is an geo-paleontological park with its museum, the .Here a baby dinosaur, the first in Italy, was discovered, in a fossil containing some internal organs