Sinkhole susceptibility map of Rome's neighborhoods updated

Many Italian cities contain "cities beneath cities," meaning tunnels, underground spaces, places of worship, and cemeteries that form an intricate network of conduits beneath the urban fabric.
These "voids" are primarily caused by the extraction of building materials and, to a lesser extent, the construction of hydraulic structures and places of worship.
When abandoned, underground spaces tend to sink, forming immense chasms.
The map, updated in July 2025, was created by ISPRA together with the CNR - IGAG Institute of Environmental Geology and Geoengineering.