Formed from the eroded remains of ancient volcanic rock, marine shell, and coral, aeolianite is a soft, porous sandstone cemented by calcium carbonate. Built up over hundreds of thousands of years as wind-driven dune fields, it hardens slowly, its interior remaining permeable and its surface vulnerable to the forces of the coast.

Salt does the sculpting. Seawater penetrates the rock and, as it evaporates repeatedly, salt crystals expand within the stone and fracture it from the inside, a process known as haloclasty. Combined with wind abrasion and the constant force of Atlantic swells, this process hollows out cavities that grow, merge, and deepen over time into the geological formations known as Tafoni: clusters of rounded, eye-like pockets ranging from small piercings to large hollows that open right through the stone.