Also known as the Basilica of Constantine, this was the last non-Christian basilica that was built on the Roman forum. It was built for trade and other administrative purposes; the entire structure required the Esquiline and Palatine hills to be leveled. Initially, there were both barrel and groin vaulted arches, but now only three barrel vault arches survive. The basilica was formed by a rectangle that was one hundred meters by sixty-five meters, dividing into a central part of a church, or nave, which was designed to hold groups of people. Three groined vaults covered the nave, and these vaulted arches extended to being thirty-five meters high. Eight Corinthian columns at a height of fourteen and a half meters supported these vaulted arches. The floors were marble and the roof was covered with gilded bronze tiles, before the looting occurred. The basilica was built during the construction of the Roman baths, and the northern vaults over the bays are hanging with no supports, proving the strength of Roman concrete and architecture.