The pyramid of Khentkaus I or step tomb of Khentkaus I is a Fourth Dynasty two-stepped tomb built for the Queen Mother Khentkaus I in Giza. The tomb, built in two phases coinciding with its two steps, was originally known as the fourth pyramid of Giza. In the first phase, a nearly square block of bedrock, around which the stone had been quarried for the Giza pyramids, was utilised to construct her tomb and encased with fine white Tura limestone.