Naples' fascinating Museum of the Underground is a DIY ode to speleologists and the treasures they uncover under the modern city. Hidden away on Piazza Cavour, its series of restored underground cisterns recreates real-life sites inaccessible to the public, from a phallocentric shrine to the Graeco-Roman god of fertility, Priapus, to a luridly hued Hellenic-era hypogeum (underground chamber). Precious debris that once filled the voids is now displayed, from rare majolica tiles to WWII-era domestic objects.

The museum was founded by veteran cave crusader Clemente Esposito, lovingly nicknamed il Papa del sottosuolo (the Pope of the Underground) in local speleological circles.