This is a prototype of "Haunted Buildings of Foligno", developed by the Quintana 4D Project.Visitors can walk around the City of Foligno to summon digital ghosts, who might reveal secrets about the places they haunt and even let them cross walls to admire wonderful hidden halls.Visitors are required to install the free app "Metaverse Browser" on their smartphones to summon ghosts and access to the augmented reality and virtual reality experiences.