"Piranesi's etchings - The existential night-mare of human existence and its infinite mysteries..."
"Giovanni Battista Piranesi (1720-1778) is arguably one of the greatest artists of architecture - of spaces both real and imagined, and certainly one of the most influential on later artists, writers and film-makers. His reputation today rests primarily on his terrifyingly original series of etchings, Carceri d'Invenzione, labyrinthine and megalomaniac prisons, but in his own day he was celebrated more for his Vedute, 137 etchings of ancient and modern Rome."
on the web
Great Book on Piranesi (Source of Above Quote)
http://www.taschen.com/pages/en/catalogue/books/classics/all/facts/02933.htm
Online Exhibit at SunSite
http://cgfa.sunsite.dk/piranesi/piranesi_bio.htm
Google Directory on Italian Architecture (Includes References to Piranesi)
http://directory.google.com/Top/Regional/Europe/Italy/Arts_and_Entertainment/Architecture/?tc=1