rises, the stones become smaller, becoming only thick at the apex. The courses are rough and irregular for the first half of its height but a narrow band of regular masonry is clear in the midsection of the pyramid. At the northwest corner of the pyramid, the bedrock was fashioned into steps. Casing stones cover the top third of the pyramid, but the pyramidion and part of the apex are missing. The bottom course of casing stones was made out of pink granite but the remainder of the pyramid was cased in Tura limestone. Close examination reveals that the corner edges of the remaining casing stones are not completely straight, but are staggered by a few millimeters. One theory is that this is due to settling from seismic activity. An alternative theory postulates that the slope on the blocks was cut to shape before being placed due to the limited working space towards the top of the pyramid. Interior Two entrances lead to the burial chamber, one that opens up the face of the pyramid and one that opens at the base of the pyramid. These passageways do not align with the centerline of the pyramid, but are offset to the east by . The lower descending passageway is carved completely out of the bedrock, descending, running horizontal, then ascending to join the horizontal passage leading to the burial chamber. One theory as to why there are two entrances is that the pyramid's northern base was intended to be shifted further to the north which would make Khafre's pyramid much larger than his father's. This would place the entrance to the lower descending passage within the masonry of the pyramid. While the bedrock is cut away farther from the pyramid on the north side than on the west side, it is not clear that there is enough room on the plateau for the enclosure wall and pyramid terrace. An alternative theory is that, as with many earlier pyramids, plans were changed and the entrance was moved midway through construction. There is a subsidiary chamber, equal in length to the King's Chamber in Khufu's pyramid, that opens to the west of the lower passage, the purpose of which is uncertain. It may be used to store offerings, store burial equipment, or it may be a serdab chamber. The upper descending passage is clad in granite and descends to join with the