A further three trial trenches were excavated by Colchester Archaeological Trust (Trenches T1, T1 extension, T2 and T3), along with mitigation excavation (ECC2912) and monitoring (ECC2911), between 2015-2017, at Colchester Garrison Alienated Land (GAL) Area B1b (previously known as Flagstaff House, now known as Arena Place).<1><2> Evaluation trenches T1 and T2 were positioned over the northern cavea of the Roman Circus. The aim of this initial phase of investigation was the establish the depth of significant archaeological contexts (Roman and later) associated with the circus, so as to inform the contractor about limits on dig-depths over the monument. Modern tarmac (EVL66, c 0.07-0.12m thick), crush (EVL67, c 0.2-0.35m thick) and buried topsoil (EVL68, at least c 0.6m thick) sealed a layer of accumulation (EVL69, at least c.0.25m thick but not bottomed). Both trenches were crossed with numerous modern services, which meant that only two small slots could be excavated over the projected route of the outer cavea. An extension was excavated to the west of T1 as it was thought that St John's Abbey precinct wall might be located here. Modern crush (WBL76), buried topsoil (WBL77) and layers of medieval/post-medieval accumulation (WBL78-WBL80) sealed natural (at a depth of c.0.85-0.9m below current ground level). Evaluation trench T3 was positioned to the southwest of the abbey gatehouse. The aim was to establish the depth of significant archaeological contexts and to record (but not excavate) those contexts. Modern topsoil (EVL188, 0.45-0.7m thick) and layers of medieval/post-medieval accumulation (EVL189-EVL191) sealed archaeological remains.<1>