With a height of 395.48 metres, the hill is composed mostly of limestone. It is a nature reserve administered by the state forestry agency of the Regione Siciliana. On the mountain is the "Sanctuary of San Calogero," from the 16th century, the Antiquarium and various natural caves which emit geothermal gas, the most well-known of which is the so-called "Stove of San Calogero." The vast area behind the settlement of Sciacca, which culminates in Monte Kronio, may be the site of an ancient volcano, which even today shows some activity, however slight, through the emission of sulphur vapours. This theory is supported by the presence of Graham Island off the coast, a volcanic island forming part of a wider "Empedoclean" system, so it cannot be ruled out that Monte Kronio was a vent of a larger volcanic system in the distant past.
Antiquarium of Monte Kronio
On the mountain there is the "Antiquarium di Monte Kronio - Stufe di S. Calogero" museum, a thermal complex and a series of karst caves which were used for health purposes in antiquity. The antiquarium was established in the 1980s and contains discoveries from local excavations. The site is managed by the Soprintendenza of cultural heritage for Agrigento.
The "Stove of San Calogero"
The cave with this name is 9.4 metres long and 4.2 metres wide and reaches a maximum height of c. 4 metres. Inside the temperature varies between 36 and 42 °C, depending on the season and time of day. Because of the high temperature, people once spent time in the cave, which was created by Daedalus in the territory of the Sicans according to legend, as a cure for arthritisrheumatism, gout, and sciatica. Seats, benches and drilled holes into which effected limbs must have been inserted were carved in the interior walls. Following a survey carried out in 1880 by professor Silvestro Zinno on behalf of the comunale council of Sciacca, the comune proposed to turn this into a spa.
In 2012 Copper Age jars dating from the fourth millennium BC were found in a cave on Monte Kronio. Organic samples taken from the jars proved to contain tartaric acid and its salt, confirming the use of the vessel as wine containers. The site is the location of one of the earliest known evidences of winemaking, dating back 6000 years, a similar age to the evidence from Areni in Armenia.
