The pyramid when completed had a height of 481 feet. It is now 451 feet high. Its base covers 13 acres. Some of the blocks of white limestone used in construction weigh 50 tons. The facing of polished stone was gradually removed for building purposes by the Arabs. On the northern side of the pyramid a narrow entrance, once carefully concealed, opens into tortuous passages which lead to the central vault. Here the sarcophagus of the king was placed. This chamber was long since entered and its contents rifled.-Webster, 1913