Immediately adjacent to the Flavian palace of Severus is the Hippodrome of Domitian or Stadium (160 x 48 m). This is a structure which has the appearance of a Roman Circus and whose name means Circus in Greek, but is too small to accommodate chariots. Hippodromes were originally areas for exercising horses, but later in Rome, Hippodrome was used to describe elongated rectangular gardens. It can also be described as a Greek Stadium that is a venue for foot races. 

However, its exact purpose is disputed. While it is certain that during the Severan period it was used for sporting events, it was most likely originally built as a stadium-shaped garden. According to a guide from the Sopraintendenza Archeologica di Roma, most of the statuary in the nearby Palatine museum comes from the Hippodrome.

On the eastern side of the Hippodrome is a large exedra decorated with sculptures and fountains commanding views of the garden below.

Domitian also built a larger stadium that was actually used for foot-racing competitions; it exists today as Piazza Navona, lo stadio di Domiziano.