1800–1650 BCE), were given Roman numerals from north to south, starting from Abu Rawash in the north. Although a few of the structures reported by Lepsius are now known to have been mastabas and other monumental structures (highlighted on the list below in light gray), the Lepsius list of pyramids is still considered a pioneering achievement of modern Egyptology. Lepsius' numerals have remained the standard designation for some of the pyramids.