His most famous monument was his step pyramid, which entailed the construction of several mastaba tombs one over another. These forms would eventually lead to the standard pyramid tomb in the later Old Kingdom. Manetho, many centuries later, alludes to architectural advances of this reign, mentioning that "Tosorthros" discovered how to build with hewn stone, in addition to being remembered as the physician Aesculapius, and for introducing some reforms in the writing system. Modern scholars think that Manetho originally ascribed (or meant to ascribe) these feats to "Imuthes", who was later deified as "Aesculapius" by the Greeks and Romans, and who corresponds to Imhotep, the famous minister of Djoser who engineered the Step Pyramid's construction.