The hippodrome, where the emperor Nero competed for Olympian laurels some 1,600 years ago, was discovered by a research team from Germany.
"This discovery is an archaeological sensation," said Norbert Muller of the Johannes Gutenberg University Mainz.
Archaeologists for years had failed to locate the remains site of the hippodrome, and it was thought that the nothing had survived, as the area had been flooded and became covered with silt.
Using geomagnetic and georadar techniques, the archaeologists discovered conspicuous, rectilinear structures stretching almost 1,200 meters. The researchers believe that this could be the racecourse, which ran parallel to the stadium.
"The project could become a new attraction for the sports world, similar to the excavation of the ancient Olympic stadium 50 years ago," Muller said.
