This great square, surrounded by colonnades, contained so many statues and other works of art that Labarte well calls it an open air museum. To the north, opposite the south-west corner of the church, was the colossal bronze equestrian statue of Justinian surmounting a pillar, which, according to Procopius, stood on seven stages of steps and was covered with bronze reliefs. The king looked to the east, and carried the orb of the earth surmounted by a cross in his hand. The pillar had originally been erected by Arcadius to support a silver statue of Theodosius his father. The statue of Justinian, which replaced that of Theodosius, was destroyed by lightning in 1492.[298] The fragments were seen by Gyllius, and, from measurements which he gives, it seems to have been from twice to three times natural size. Bondelmontius says the pillar was seventy cubits high. A very good drawing of the statue, now amongst the MSS. of the Serai library, made about the year 1340, is reproduced by Mordtmann. This pillar and its statue is often called the Augusteum, and it probably gave its name to the place in which it stood. _The Milion._--It is probable that the city milestone existed before Constantine, who may have built the structure over it. According to Du Cange[299] the Augusteum, with which it was so closely associated, was often called by its name; so that Codinus tells us that the church of S. Phocas was built “in the Milion.” It appears to have formed the western boundary and gate of this forum, or at least of its inner part, if divided, and to have been connected with a colonnade running north and south as well as with the _Mese_. It is spoken of as a colonnade (_embolos_), as vaulted (_kamara_ and _phournikon_), or as having many arches (_apsides_). Cedrenus and other writers speak of statues in the apsis or kamara of the Milion. It can hardly be doubted that it had four large arches facing different ways. A structure of this kind remains at Lattaquieh, which is about ten metres square and was surmounted by a dome. De Vogüé[300] compares it with ruins of a similar erection found at Palmyra, the Mesomphalion of Nicaea, and the Umbilicus of Antioch described by Dion Chrysostom, and others. This last stood at the centre of the two great colonnaded streets that ran east to west and north to south through the city.