Deep within the Great Pyramid of Giza in Cairo are four narrow shafts, discovered in 1872—the two shafts in the “King’s Chamber” extend to open air, but the two in the “Queen’s Chamber” disappear puzzlingly into the architecture. Academics have long debated their purpose , but because no human could access the narrow spaces, no one could confirm their theories—but now we can send robot explorers instead. In 2011, the University of Leeds designed and built a robot as part of the Djedi Project, specifically for scoping out virtually inaccessible archaeological sites. The robot is well-equipped with a coring drill, a miniature robot that can fit through 19 mm holes, and an ultrasonic device that can determine the thickness of walls. It also has a “micro snake” camera that can see around corners, and on a mission through the shafts into a tiny hidden chamber, the Djedi robot sent back images of 4,500 year old markings. Researchers pieced these images together to reveal hieroglyphs marked in red paint. Red-painted numbers and graffiti are quite common around Giza—they’re often marks from masons or work gangs, depicting numbers, dates and names. These particular markings have not been seen by human eyes for thousands of years, and archaeologists think they might help us understand the purpose of the mysterious shafts.