Using selected sound materials from Sonorous stones, Stalactites, Bat calls, Flutes, Field recordings collected by Mariolina Zitta in different caves in Liguria a Sardinia, Italy, processed and edited by Alio Die.   In "Lithos" the drones are played by the authors on a set of long stones that goes in resonance, caressed by a bathed hand, by the same principle of the crystal's glasses. 
A very immersive and obscure traveling, an underground meditation with a ritual touch, in accord with the "natural sound", despite the sampling and multieffect techniques used here. 
A deep listening experience.