section_path: Interior/Subterranean Chamber
section_name: Subterranean Chamber
paragraph_text: Subterranean Chamber
  
  The Subterranean Chamber, or "Pit", is the lowest of the three main chambers and the only one dug into the bedrock beneath the pyramid.
  
  Located about 27 m (89 ft) below base level, it measures roughly 16 cubits (8.4 m; 27.5 ft) north-south by 27 cubits (14.1 m; 46.4 ft) east-west, with an approximate height of 4 m (13 ft).The western half of the room, apart from the ceiling, is unfinished, with trenches left behind by the quarry-men running east to west. A niche was cut into the northern half of the west wall. The only access, through the Descending Passage, lies on the eastern end of the north wall.
  
  Although seemingly known in antiquity, according to Herodotus and later authors, its existence had been forgotten in the Middle Ages until rediscovery in 1817, when Giovanni Caviglia cleared the rubble blocking the Descending Passage.
  
  Opposing the entrance, a blind corridor runs straight south for 11 m (36 ft) and continues with a slight bend another 5.4 m (18 ft), measuring about 0.75 m (2.5 ft) squared. A Greek or Roman character was found on its ceiling with the light of a candle, suggesting that the chamber had indeed been accessible during Classical antiquity.
  
  In the middle of the eastern half is a large hole called a Pit Shaft or Perring 's Shaft. The uppermost part may have ancient origins, about 2 m (6.6 ft) squared in width and 1.5 m (4.9 ft) in depth, diagonally aligned with the chamber. Caviglia and Salt enlarged it to the depth of about 3 m (9.8 ft). In 1837 Vyse directed the shaft to be sunk to a depth of 50 ft (15 m), in hopes of discovering the chamber encompassed by water that Herodotus alluded to. It is slightly narrower in width at about 1.5 m (4.9 ft). No chamber was discovered after Perring and his workers had spent one and a half years penetrating the bedrock to the then water level of the Nile, some 12 m (39 ft) further down.
  
  The rubble produced during this operation was deposited throughout the chamber. Petrie, visiting in 1880, found the shaft to be partially filled with rainwater that had rushed down the Descending Passage. In 1909, when the Edgar brothers' surveying activities were encumbered by the material, they moved the sand and smaller stones back into the shaft, leaving the upper part clear. The deep, modern shaft is sometimes mistaken to be part of the original design.
  
  Ludwig Borchardt suggested that the Subterranean Chamber was originally planned to be the burial place for pharaoh Khufu, but that it was abandoned during construction in favour of a chamber higher up in the pyramid.