Following the Boudican revolt of AD 61, Colchester was re-established as a colonia, and remained so for around 300 years. The re-foundation of the city after the revolt involved the resurrection of the street grid and the reuse of some of the pre-Boudican building plots.
The town wall appears to have been built sometime between AD 65 and AD 80 and was deliberately designed to include space for expansion of the settlement to the north and east of the original colonia. The wall itself is significant as it may be the earliest wall of its kind in Roman Britain, and unlike town walls elsewhere in Britain, it appears to have been freestanding. Once completed the wall was approximately 2,800 metres long, 2.4 metres thick and rose to a height of about 6 metres. Extant sections of this wall can be seen in several locations, especially along Balkerne Hill. Six gates were built into the wall, along with a series of rectangular towers. A V-shaped defensive ditch was cut around the outer foot of the wall.
The later Roman town of Colchester had numerous public buildings which enabled it to function as an administrative and cultural centre. Numerous substantial buildings have been excavated within the town, many of which are likely to have been public buildings, although it has often proved difficult to determine their function. One of the buildings that has been positively identified is the Roman theatre. This substantial D-shaped stone building stood to the west of, and adjacent to, the Temple of Claudius and would have been large enough to accommodate a seated audience of at least 3,000. To the south of the town, at Gosbecks, a second Roman theatre survives as a mound about 1.5 metres high. This was the site of an early Roman timber theatre which was replaced by a turf and timber theatre in the 2nd century AD. This theatre had a capacity of around 5,000, making it the largest theatre of its kind in Roman Britain. The remains of a Roman circus were discovered in 2004, during investigations in advance of the redevelopment of Colchester Garrison, approximately 400 metres south of the walled town. It is significant because it is the only known example of a Roman circus in Britain.
The domestic and commercial buildings in Colchester took a variety of forms. In the immediate aftermath of the Boudican revolt the majority of new buildings appear to be relatively modest structures. The 2nd century AD appears to have seen considerable growth within the town, and the scale of residential buildings appears to increase significantly, with the appearance of large town houses often laid out around a courtyard. Many of these houses included internal features such as hypocausts to provide heating, tessellated pavements and mosaic floors. The construction of large town houses continued in the earlier part of the 3rd century, but by the 4th century there appears to be a decline in construction work. Some occupied buildings appear to be partially derelict, but at around the same time some high status buildings are still undergoing significant refurbishment.