Casmenae or Kasmenai (Casmene in Italian) was an ancient Greek colony located on the Hyblaean Mountains, founded in 644 BC by the Syracusans at a strategic position for the control of central Sicily. It was also intended as a military forward-position on the Via Selinuntina road that connected Syracuse to Akragas (modern-day Agrigento) - also on that road were Gela and Akrillai to Casmene’s west and Akrai to its east. Destroyed by the Romans in 212 BC, Casmene was abandoned during the 3rd century BC and never inhabited again.
The site was discovered by the Sicilian archeologist Paolo Orsi during the first half of the 20th century, after he had identified the most probably site at Monte Casale in Buscemi at 830m above sea level, on an extinct volcano near Monte Lauro, 7 km from Giarratana and 12 km from Palazzolo Acreide. Remains of the defensive walls, long 3.400m, are still visible with the base of one of the temples and some dwellings.