Probably the most famous of all Aldine books is the Hypnerotomachia Poliphili of Francesco Colonna. Admired for its beautiful illustrations and typographical arrangement, the work is a peculiar mixture of fable, history, architecture, and mathematics written in an odd hybrid of Latin and Italian. Apparently because of the somewhat erotic nature of some of its illustrations, the Hypnerotomachia is one of the few books printed by Aldus in which he did not identify himself as the printer. The illustrations have been especially prized over the years, and they are therefore missing from many copies of this book. The BYU copy is complete, but it is not perfect; a few pages containing illustrations, earlier removed, have been replaced with pages from other copies.