Flint flakes and pottery of the Castelluccio facies attest to human presence as early as the Copper Age, followed, between the 9th and 7th centuries BC, by a Sican–Sicel settlement engaged in pastoralism and the control of grain trade. In the 6th century BC, the arrival of colonists from Akragas triggered a rapid process of Hellenization: the village was transformed into a fortified phrourion (a kind of military base), surrounded by walls of rusticated blocks and equipped with a massive square tower, unearthed during the 1984 excavations. Inside the enclosure, the foundations of a small archaic temple and domestic spaces are visible, where oil lamps, painted jugs, a terracotta female bust, and the head of a votive figure were discovered—evidence of a cult tied to the fertility of the soil. At the slopes, two rock-cut necropolises extend: the tombs, dug into the soft calcarenite, yielded red-figure kraters, pyxides, and lekythoi, reflecting the lively circulation of goods between the indigenous world and the Siceliot workshops.
Research began in the mid-19th century with Francesco Landolina and Antonino Salinas, continued in the 1950s under the direction of Dinu Adameșteanu, and concluded in 1984 with the completion of the fortification plan. The most significant finds, including the refined gilded silver phiale for libations, are now on display in the Regional Archaeological Museum of Caltanissetta.
The site, without ticket office and freely accessible, can be reached by car along the SP 122: a short marked path leads in about ten minutes to the panoramic summit, from which the view embraces the almond-covered hills and the ancient sulfur mines. Educational panels illustrate the chronological phases, and in the summer months volunteer guides organize sunset tours. Walking among the remains of Gibil Gabib means reliving the encounter of cultures that shaped the heart of the island, grasping at once the archaic verticality of the acropolis and the broad horizon of the Nisseni countryside.