The spina, the barrier running down the middle of the track, is exactly 1000 Roman feet (296 m) long, and would have been cased in marble. Its many ornaments, including cones, metae and obelisks, would have cast shadows across the track in the late afternoon sun. In the centre stood the Obelisk of Domitian which Maxentius presumably had moved from the Isaeum as part of the tribute to his son.
The spina, a 1000 Roman feet (296 meters) long marble barrier dividing the track, was decorated with cones, metae, and obelisks that cast shadows in the late afternoon sun. The Obelisk of Domitian, moved from the Isaeum as a tribute to Maxentius' son, stood in its center.