"By 1532, Giulio Camillo, a professor at Bologna, suggested a means for transforming the mind through a uniquely powerful memory system of his own creation."

"The Memory Theater of Giulo Camillo, as it came to be known throughout sixteenth-century Europe, consisted of a wooden memory palace shaped in the form of a Roman amphitheater."

Writes Richard Restak in "The Complete Guide to Memory: The Science of Strengthening Your Mind," pointing to this visualization:

Restak continues: