A subsurface detection probe fitted with a periscope or camera and light source, used to examine subterranean chambers - most often Etruscan tombs. The Lerici Foundation of Milan and Rome has had great success with this method since the development of the periscope, first used in 1957 in an Etruscan tomb in the cemetery of Monte Abbatone. The periscope is inserted into the burial chamber and can photograph the walls and contents of the whole tomb.