erected A.D. 310, the enclosure walls of which have been preserved
almost entire. These display the interesting phenomenon of pots of
earthenware built into them, which not merely expedited the progress
of the work, but allowed of its being more easily repaired than was
possible in any other mode of construction. Its length was 1574 feet,
and breadth 269, and 18,000 spectators could be accommodated within
its vast walls, yet it was a small building compared with the Circus
Maximus (see page 209). In 1825 three inscriptions were found proving
this to be the circus consecrated to Romulus, son of Maxentius. Two
towers flank the entrance, supposed to have been the seats for the
judges. It is the most perfect specimen of a Roman circus remaining.
_On the top of the hill_ is the "stern round fortress of other days,"
known as