The Fucino Valley is a plateau of the Marsica, in the Province of Aquila, at an altitude of between 650 and 680 m, endorheic, that is in a situation by which the waters of the surrounding areas naturally flow towards the plain and is landlocked, encircled by mountains such as the Vallelonga and the Sirente-Velino Range. The plateau takes it's name from the pre-existent carsic lake Fucino, the third in Italy for it's size, that, due to it's irregular water levels, was the object of numerous tentatives to regulate it since Roman times. The lake was once known as lake Forco according to the Greek poet Licofrone; for other ancient authors it was lake Vulsci in memory of the Roman defeat of three thousand Volsci on the lake sides; up to the last century it was also known as lake Celano. With all probability the name Fucino was due to the presence of a red algae that in certain periods of the year give the lake a colour similar to that of a forge fire or "fucina".