They are gorges up to 25 meters high and 2 meters wide in the narrowest points and 4-5 meters in the widest points. The natural canyon was excavated over thousands of years by the water which gradually brought to light the lava body, with typical vertical cracks ^[1].

The Alcantara river flows between lava rock which forms its bed characteristic. On the territory of Motta Camastra in Fondaco Motta is the most impressive gorge and famous Alcantara, more than 6 km long and easily passable for the first 3.

The peculiarity of this gorge consists in the structure of the walls, created by flows of lava basaltic (low in silicon but rich in iron, magnesium e football). The lava then cooled very quickly creating prismatic shapes pentagonal ed hexagonal, which recall the molecular structure of the materials that constitute it.

The appearance of the river in the stretch of the Gorges is believed to date back to the magma flows of the last 8,000 years. The most recent theses identify three successive flows from fissures and vents that opened in the area of ​​Monte Dolce, in the middle-lower side of Etna; the flows are shown superimposed along the left wall of the river. The oldest lava flow is the one that reached Capo Schisò, on the sea. The columnar basalts visible in the Gorges are those of the less ancient flow and would be the product of the rapid cooling caused by the presence of the river water; they form prismatic structures of different configurations, "stack", "harp", radial. The vertical "organ pipe" formations reach 30 m in some cases^[2].