Gravina (Apulia) has a dual soul: part of the Alta Murgia National Park, it is covered in houses, churches and ancient buildings on the surface, but also has a secret heart that beats hidden underground.
Popular geologist Mario Tozzi has explained, “the long and narrow crevices known as ‘gravine’ are such a predominant feature in Apulia’s calcareous land that some places – such as Gravina di Puglia – have been named after them.”
“At the very center of the town, the hollow subsoil is a coalescence of dozens of cellars, dug by hand, where for centuries people fermented wine and stocked wheat.”
“Gravina was founded on relatively recent calcareous sands (the scientific name is calacarenites, but everyone here calls them ‘tufi’), carved since the 8th century BC – first to widen caves and later to make extremely light and resistant bricks, which could be used even to build right on the edge of the abyss they had been taken from.”
“The underground landscape here constantly changes: […] there are clear signs of intense water erosion, producing actual ‘giant vats’ […]. There is no separation as calcarenite turns into bricks and into manmade structures: here, natural erosion and pillars holding up great underground arches belong to the same context – somewhere between nature and city” (translated from M. Tozzi, “Italia segreta. Viaggio nel sottosuolo da Torino a Palermo”, Rizzoli, Milan 2010).