Archaeologists who arrived at the scene then discovered the 500-year-old remains of an adult man believed to be a medieval knight or nobleman, buried near the foundations of a 13th century Blackfriars Monastery.
Scientists will study the corpse's bones and teeth to learn more about the man's life and cause of death.
According to the Daily Mail, the knight would have paid dues throughout his life to make sure he would be buried there.
"We obviously knew the history of the High School Yards site while we were studying here, but I never imagined I would be back here to make such an incredible discovery," Headland Archaeology's Ross Murray, a former student at the University, told The Scotsman.
"We used to take breaks between classes just a few feet away from the building’s doorway – and all the time the grave was lying under the car park," he added.
Richard Lewis, of the Edinburgh City Council, said the surprise find had "the potential to be one of the most significant and exciting archaeological discoveries in the city for many years, providing us with yet more clues to what life was like in medieval Edinburgh."
It was only a month ago that archaeologists discovered a similar burial site -- the remains of England's King Richard III were found in a parking lot in Leicester, England.