The At Meydanı is the square in front of the museum, it is the former Roman hippodrome. The date of its first design is unclear, some say it was done under Septimus Severus (193-211 AD), and completed under the Roman Emperor Constantine (272-337). There being no archaeological proof for this the more general opinion is it dated from 330-337 after Byzantium was declared to be the new capital of the Empire in May 13th 330 AD.
Under Ottoman rule it maintained its position as the place for major events, such as festivities after weddings and circumcision, for horse racing, javelin throwing. Some of the remains are on display at the museum.