Inside the seating substructures. It has long been thought the hippodrome, to the northwest of the Hadrian Gate, was a naumachia, however, it was in fact a hippodrome. Actual races are still held here, I didn’t see any, I saw some horses being run here though. It is 244 meters of length, its width reaches 50 meters. Some 16 to 17 rows could hold 15000 visitors. At the south side ten starting positions were available, probably two towers flanked that part. It seems to have been built around the mid-2nd century AD, was in decline in the 3rd century, and may have been used as a polo playing field by Persians who were quartered in the town in 614.
<a href="//commons.wikimedia.org/wiki/User:Dosseman" title="User:Dosseman">Dosseman</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>