* This name, found only in the Regionary Catalogue (Region V
), belongs without doubt to the structure of which some remains are still visible, near the SESSORIUM
(q.v.). Castrense is to be explained as meaning' belonging to the imperial court,' and the brickwork is that of the time of Trajan 1
(AJA 1912, 415
, 417), who was especially fond of buildings of this kind. It is possible that this is the θέατρον μέγα κυκλοτερὲς πανταζόθεν
mentioned by Pausanias (v. 12. 6) as one of the most important buildings of Trajan.
It was elliptical in form, with axes 88.5 and 78 metres in length, and constructed entirely of brick and brick-faced concrete. The exterior wall consisted of three stories of open arcades, adorned with pilasters and Corinthian capitals. When the Aurelian wall was built, the amphitheatre was utilized as a part of the line of fortification, the wall being joined to it in the middle of the east and west sides. The outer half of the building was thus made a projecting bastion, and the open arcades of the exterior were walled up, the ground level outside being at the same time lowered. The inner half was evidently pulled down, so that little use can have been made of the edifice at that time.
Drawings of the sixteenth century represent all three stories, but since that time the upper one has entirely disappeared and all but a few fragments of the second. The cavea and the wall of the arena have also been destroyed, so that the remaining portion consists of the walled-up arcades
of the lowest story (HJ. 248-249; RE iii. 1773
; LR 386; LS iii. 164
; DuP 132). See Ill. 1, which shows its condition in 1615; ASA 96.