Remains discovered in 1868 were identified and interpreted as the site of the theatre following excavations by the Canterbury Excavation Committee in 1950-56 at 3 St Margaret's Street. The theatre was of two periods and was in existence by AD100. The theatre was completely remodelled on a classical plan cAD210-26. The two outer walls of this theatre were found, divided by a corridor floored with opus signinum, 9ft wide. The entire surviving structure was of flint with tile courses, but there is evidence to suggest that the superstructure was of stone. Some details of the substructure were recarved, including the foundations of a possible staircase and of walls which supported the seating above. The theatre had probably been demolished by the middle of the 12th century. Foundations of part of the Cavea, which supported the theatre's banked seating and a section of an opus signinum floor which was originally part of curved walkway was found during excavations in the back garden of No 25 Watling Street in 1987.