The Colchester circus is orientated east to west and measures 448.2m in length and between 71.1 and 74.2m in width. The area of the Scheduled Monument also includes a 10m buffer zone around the circus which is considered necessary for the support and preservation of the monument.

Three area excavations and a number of evaluation trenches have been investigated and all contribute to our understanding of the form and fabric of the circus. Most recent excavations (2007) by the Colchester Archaeological Trust have exposed a section of the spina at the junction between Napier Road and Circular Road North. All the evidence helps to illustrate and confirm the archaeological potential of the monument. It has been calculated that the circus had a seating capacity of around 8000 - 15000. The starting gates are thought to have been situated at the western end of the structure with the semi circular end to the east. The stand or cavea at Colchester varied between 5.8m and 6.0m in total width. It was built of earth but was retained by stone or timber walls, a similar method of construction to that found in theatres and amphitheatres in Britain and elsewhere. At Colchester it is thought the inner cavea was built of stone. The large exterior buttresses with parallel, less substantial walls 5m inside imply the outer cavea wall was of stone and has been estimated to be at least 2m in height. These may have supported blind arcading enhanced with pilasters much like examples on the continent. Finds from robber trenches certainly confirm the presence of Romanised decorative architecture such as tile coursing, opus signinum facing mortar (fine Roman concrete) and a piece each of column and incised marble facing (possibly Purbeck) The stone used in the foundations of the cavea is greensand which is rare elsewhere in Colchester probably because it had to be bought in from Kent. On the whole dating evidence from the circus is limited but based on the dated contexts of the stone elsewhere in the area the use of Kent greensand implies it was built in the second century AD. The sheer scale of the building was so great that it is believed that the emperor must have paid for its construction. Hadrian’s visit to Britain in AD 122 is associated with a revival of public buildings in towns and it is thought that he may have been responsible for the construction of the circus at Colchester. A number of glass and pottery finds discovered in Colchester in the past depict images of chariot races. Given the discovery of the circus it is now thought that some of these may be souvenirs of actual events. New finds associated with the sport include a piece of horse furniture which was recovered from the robber trench of the inner wall A coin from a grave dated to the early first century AD features a four horse chariot and rider and is a rare find in Britain. A silver coin found in a rare hoard dated to between 150 BC and AD 117 also depicts a four horse chariot. It is unclear when the circus came out of use but analysis suggests the circus was probably levelled in the late Roman period, whilst the footings were subsequently robbed in the medieval period.

Early medieval pottery from a trench dug to extract building material suggests that some material may have been dismantled and used in the abbey construction. The abbey precinct wall exhibits some odd bends in the south west corner and implies that its alignment may have been, at least in part determined by elements of the surviving circus. A section of the precinct wall lies approximately 60m west from the eastern end of the monument. It stands to almost 2.5m high and although there is evidence of dressed facing stone it survives mainly as a randomly coursed stone core. This section of walling is included in the scheduling.

Excavation also confirmed that the circus was surrounded by a contemporary cemetery. A total of 516 burials have been excavated and recorded. The known areas of the cemetery have been fully excavated and preserved by record and are not therefore included in the scheduling.

All buildings, with the exception of the upstanding precinct wall are excluded from the scheduling as are all road and path surfaces, fences signage and tennis courts. However, the ground beneath all these features is included.