Sphinx Passages

There are several holes and passages in the Great Sphinx at Giza. Some are of known origin but others are not.
There is a hole on the back of the Sphinx, about 4 feet behind the head. It was made by Howard Vyse in the 1840s and has been dubbed Perring's Hole after his engineer. Seeking chambers, Vyse bored a hole 27 feet deep but the drill rod became stuck. He tried using gunpowder to remove the rod, but gave up so as not to do further damage to the Sphinx. The cavity Vyse created was cleared in 1978 by Zahi Hawass, and inside it he found a part of the Sphinx's headdress.
Later, in the 1850s, August Mariette cleared out a shaft on the Sphinx's back, which he realized was nothing more than a widening in a natural fissure. (He also found the peculiar masonry "boxes" against the body of the monument).
In 1923, Department of Antiquities director Lacau and engineer Emile Baraize began an 11 year excavation of the Sphinx area. In December 1925 a photograph was made by the team showing the area of the large masonry box on the south side of the Sphinx. Loose stones can be seen, stones cut for repairs, but in the side of the Sphinx body a large gaping entrance, or perhaps grotto is visible. It was covered up in the restoration. Further conservation included lining the largest fissure on the Sphinx's back (some 6 feet wide) with limestone blocks and covering the resulting shaft with an iron trap door.
Baraize also paved with cement a deep hole on the top of the Sphinx's head. The hole measures approximately 5 feet square and nearly 6 feet deep. An iron trap door was fitted to the mouth of the hole. It has been theorized that the hole, began as a means for affixing a headdress to the sphinx in the manner of the New Kingdom (see photo below), was later deepened in search of hidden chambers.

Tutankhamun's calcite sphinx, Luxor Museum.

In 1980, Zahi Hawass uncovered a passage beneath the casing stones leading under the Sphinx (see photo below). He was informed of the passage by two elderly workers who had worked with Baraize (the tunnel had not been documented and had nearly been forgotten). The passage is on the north side near the tail and has two parts at right angles to each other. One descends for 13 feet, terminating in a dead end. The upper part runs for about the same length and ends at a small niche (about 3 feet wide and 6 feet high). Items found among the limestone chips and sand included bits of charcoal, small ceramic particles and other pottery shards, an alabaster chip, a granite chip, part of a modern water jug, a piece of tin foil, another fragment of red granite, and two old but modern leather shoes. It is possible that the passage was made by Vyse, who had mentioned in his journal that he had bored "near the shoulder, and near the tail," without providing further details.

Passage at rear of Sphinx
(bottom left of center).

There is an iron trap door fitted to the ground within the Sphinx's paws, between the Thutmose IV Stela and the chest of the Sphinx. This is not a passage but rather a somewhat rectangular pit that was covered with a cement roof and iron beam then sealed with a trap door by Baraize as a part of his restoration efforts in the 1920s.
There is another shaft in the Sphinx enclosure but not connected with the Sphinx itself. The so-called Keystone Shaft is in the floor of the enclosure under the north ledge of the wall, just opposite the north hind paw. The passage measures about 4.5 feet by 3.5 feet and is just over 6 feet deep. A large piece of basalt, with one side finished smooth, was found inside the shaft. It is likely that the passage was meant to be a tomb but was never completed.