» Grotta del Vento    Known as Wind Cave. Offers 3 different tours. Includes hours, fees, photo gallery, map directions and contact information. Located in Tuscany. [English, Italian, French and German].    http://www.grottadelvento.com/

» Le Grotte di Frasassi    Offers 70-minute trips and several longer, off-track excursions. Includes hours, rates, photos, history, nearby attractions and activities, and contacts. Located in Genga. [English, Italian, German, French and Spanish]    http://www.frasassi.com/

» Orvieto Sotterranea    Guided tours to the underground of Orvieto. Information, prices, booking.    http://www.orvietosotterranea.it/en/