Domitian Stadium, also known as the Stadio di Domiziano, was an ancient Roman stadium located in Rome. Built in the 1st century AD under the reign of Emperor Domitian, it was primarily used for athletic competitions and other public events. The stadium could accommodate around 20,000 spectators and featured a rectangular shape, typical of Roman design. The structure was notable for its impressive architecture, including a long track for races and seating areas for spectators. Today, remnants of the stadium can be found beneath the Piazza Navona, which was constructed over its ruins, showcasing the historical significance of this ancient venue.