Significant archaeological remains were recorded during a watching brief by Colchester Archaeological Trust at the Grey Friars Hotel (former Grey Friars Adult Community College), High Street, Colchester. The existing buildings on the site were largely retained, but with some internal and external alterations. These included the construction of a covered entrance foyer and a lift shaft. Several of the existing walls in the area of the entrance foyer and the lift shaft needed underpinning. The services across the site were upgraded, and the hotel grounds to the north of the buildings were remodelled. The public car park to the east of the hotel site remains in use, although its layout was modified.<1> The limited structural alterations to the existing buildings included the construction of a covered entrance foyer in a yard area between Grey Friars and All Saints House. Also, a lift shaft was attached to the rear elevation of the eastern Edwardian wing of Grey Friars. The lift enclosure measured approximately 3m east-west by 2.5m north-south, and extended approximately 1.5m deep below the modern ground level. Prior to the construction of the lift enclosure, a drain was laid beneath it. The drain extended from west to east along a narrow yard area. The trench for the drain was 500-700mm wide and approximately 2.0m deep. The yard area was subsequently infilled. Several of the existing walls in the area of the entrance foyer and the lift shaft needed underpinning. This involved the digging of trenches by the contractors alongside and below the existing wall foundations. The depth of the trenches varied from approximately 1.7m to 2.5m below the modern ground level. The existing foundations were between 1.0m and 1. m deep. In addition, structural supports were inserted into a cellar beneath the north-eastern part of Grey Friars. The cellar is situated below the single-storey block to the north of the lift shaft. Two small holes, each approximately 900mm square and 550mm deep, were dug in the brick floor of the cellar to take steel supports. The cellar floor lay roughly 3.2m below the existing ground floor level within Grey Friars. A number of other minor alterations took place to the existing buildings to form the accommodation and other facilities. This included the construction of an external east wallfor the single-storey block in the north-eastern corner of Grey Friars. As the contractors dug the foundation trench, a modern well or soakaway was uncovered, and this necessitated the redesign of the foundation. The redesigned foundation consisted of a ground beam, set in a trench approximately 1.1m deep and 900mm wide. This rested on deep pad foundations at either end. The northern one was L-shaped and was approximately 2.4m deep, while the southern one was square, approximately 3.4m deep. Several other foundation trenches were dug by the contractors, mostly for internal walls within Grey Friars and All Saints House. The upgrading of the drains and other services involved the contractors digging numerous trenches in and around the existing buildings. Those trenches outside the existing buildings were usually dug by mini-digger, while others, especially those inside, were dug by hand. The trenches varied considerably in size and depth, although those inside the existing buildings were usually fairly shallow (ie. Less than 1m deep). Many live and redundant services were encountered during the watching brief. A few small trial-holes were also dug by the contractors at different points around the site. In addition to the trenches for services inside the existing buildings, the floor levels over larger areas, including whole rooms, were lowered by hand in several places. For example, an east-west corridor between the 18th-century part of Grey Friars and the Edwardian west wing was lowered by approximately 800mm. Similarly, the floor level in the room immediately to the east of the corridor was lowered by up to 1m, and the north wall of this room was underpinned. Work also took place within the hotel grounds to the north of the existing buildings. A trench was dug by the contractors for the foundations of a boundary wall along the eastern side of the hotel site. From the north-east corner of All Saints House, this extended northwards for approximately 74m, with a gap for an entrance about two-thirds of the way down. The trench was approximately 1.1-1.2m wide and 700-800mm deep. In addition, trenches were dug by the contractors for the foundations of low retaining walls around the edges of the terrace to the north of the 18th-century part of Grey Friars. These trenches were approximately 700mm wide and 700mm deep. Among other work that took place in the hotel grounds was the remodelling of the car parking areas. Following some exploratory excavation by hand by CAT staff, the contractors machine-dug a large rectangular trench for a soakaway in the car park at the northern end of the site. The trench measured approximately 10.5m by 5.2m. The eastern part of the trench was dug roughly 2m deep, but the western part had to be dug up to 3.75m deep to remove the backfill of a large post-Roman pit. The northern car parking area was subsequently extended southwards. This involved ground reduction by machine of a rectangular area, measuring approximately 21m east-west by 6.5m north-south. Stripping took place up to a depth of 1.4m in this area. Also, a north-south trench was dug by machine southwards from the eastern part of this stripped area. This trench was approximately 10.2m long and 1.6m wide, and was dug to a depth of 700-750mm below the modern ground level. Subsequently, stone-filled gabions were housed in the trench. The public car park to the east of the hotel site was also remodelled, although most of the changes did not involve significant ground disturbance. However, in the northeastern part of the car park, a trench was dug for a soakaway and narrow pipe trenches were dug to the west and south-east of it. The trench for the soakaway was approximately 1.9m square and 2.75m deep. The pipe trench to the west was approximately 600mm wide and 1m deep. That to the south-east was 700-750mm wide, and varied in depth from approximately 850mm, close to the soakaway trench, to 1.9m deep at the south-eastern end of the pipe trench, adjacent to an existing manhole. The groundwork was monitored by CAT staff during intermittent site visits. Machining of the deeper trenches in the more archaeologically sensitive areas was monitored continuously. The machining was carried out using a mechanical excavator with a toothless bucket. CAT staff were given time by the contractors to investigate and record any archaeological remains uncovered, and to collect up the finds unearthed. On health and safety grounds, the recording of archaeological deposits in the deeper trenches, notably during theunderpinning and in the trenches for the soakaways, had to be done from the modern ground level looking down into the trenches. The natural subsoil consisted of brownish-yellow gravelly sand (Layer or L6). This was capped in places by shallow pockets of pale brown cover loam. During much of the watching brief, the natural subsoil was not reached, but it was exposed in some of the deeper trenches. For example, at the northern end of the entrance foyer area, between Grey Friars and All Saints House, the top of the natural subsoil lay roughly 2m below the modern ground level (Sx 4). In a trench for a soakaway at the northern end of the hotel site, the natural subsoil (L6) lay approximately 1.15m below the modern ground level (ie in places where no significant archaeological or modern features were present) (Sx 1). In the public car park to the east, in a trench for another soakaway, the natural subsoil (L6) was reached at approximately 1.55m below the modern ground level (Sx 5). In a pipe trench some 18m to the south-east of the soakaway, L6 was roughly 1.85m deep (Sx 2). In several places on the site Roman deposits were observed, including the floors of a Roman building in the entrance foyer area between Grey Friars and All Saints House. Medieval remains in the vicinity of the existing buildings were sparse, although a pit was uncovered that possibly predated the Franciscan friary. Machine-trenching in the hotel car park at the northern end of the site revealed a large medieval pit, which had probably been dug for sand and gravel extraction. Further east, in trenches in the public car park, archaeological deposits associated with the demolition of the friary buildings were uncovered, including two north-south robber trenches and a layer of demolition debris. Among the other remains exposed on the site were post-medieval and modern foundations, floors and pits. During the underpinning of an internal wall within Grey Friars, a probable Early Bronze Age flint dagger was discovered by a workman.