The Anapo river – whose name, of Greek origin, means “invisible” – has its source in the territory of Palazzolo Acreide, and initially flows through a deeply eroded valley, which widens and narrows. Close to the town of Palazzolo, the valley begins to show the characteristic shape of a canyon, slipping through layers of hard rock in which it has excavated tortuous and steep paths with narrow and high meandering walls, known as Gole (Gorge) di Pantalica. It is here in this area – after the bridge of Cassano-Ferla and the meanders of the district of Giambra, in the town of Sortino – that is located the world famous Necropolis of Pantalica, one of the largest in the Mediterranean regions, with its hive of thousands of ancient tombs distributed along the rocky walls, used from prehistorical ages to the early Christian era. Today much of the Anapo valley, including the area of the necropolis, is protected by the Naturalistic Reserve Pantalica and Anapo Valley. From the naturalistic point of view, the predominant vegetation is the typical Mediterranean maquis. In the valley there are the typical “oriental” plane trees, black and white poplars, willows, and a rich and fragrant underwood; the less steep slopes are colonized by large oaks and holm oaks. In the flattest areas it is spectacular the explosion of spring flowers, iris, crocuses, daffodils and many species of wild orchids. The area is populated by mammals (foxes, rabbits, weasels, martens, porcupines), birds (falcons, buzzards, eaglea, red kitea, long-tailed bushtits, dippers), reptiles, among which the leopard snake, and insects, like the black dragonfly. A series of paths closed to cars allow to go trhough the valley to reach the archaeological site of Pantalica. The settlement of Pantalica grew up on the ledge at the confluence of the Cava Grande torrent valley and the Anapo river valley. This ledge is connected to the plateau located behind only by a narrow isthmus, called Sella di Filipporto, or “Gate of Pantalica”. The hill lies with high cliffs overhanging the bed of the two rivers, wedged in narrow gorges. The vast backdrop of five separate necropoles, precious remains of prehistoric cities, is marked by thousands of burial caves carved into the cliffs. The oldest (the necropolis north-west and the vast northern necropolis) date back to the XI-XII centuries BC, while the most recent (the side groups called Filipporto and La Cavetta) date to the centuries between the ninth and eighth B.C. Of the ancient town are still visible the ruins of the megalithic royal palace, or Anaktoron (VIII century BC), at the midpoint of the plateau overlooking the valley, and the fortifications of Porta Pantalica. The city was founded by indigenous pre-Greek populations coming from the coast and developed at the end of the Bronze Age and beginning of Iron Age. However, the name Pantalica is Byzantine (historical phase of which are preserved many vestiges: houses, tiny churches and oratories), while the ancient name is not revealed by the historical sources: according to some theories Pantalica could identify with the ancient Hybla, the main settlement of the area in the Pre-Greek period.