During excavations undertaken by Canterbury Archaeological Trust, ahead of the rebuilding of the Townwall Street filling Station, Dover, a complex series of stratified archaeological deposits were revealed representing activity at the site between the early Medieval period and later post medieval periods. Period 4 consists of some somewhat fragmentary post medieval remains which largely consisted of wall footings relating to buildings and garden boundaries. Post war clearance of the site appears to have truncated most of the associated stratified remains. Cartographic and documentary evidence shows that a large mansion once stood in the area of the present site. Some of the remains recorded in the excavations have been equated with this important building and its associated structures. These include possible wall footings of the mansion itself, a culvert, a boundary wall along Clarence Street and garden walls.

The grounds of the mansion has been laid out across an area previously occupied by early post medieval buildings fronting onto the southern side of Clarence Street. These buildings must have been swept away, together with the long established property divisions, when the mansion was first laid out on a new axis. (1) The construction date of the mansion is not certain, the earliest map to show the building is Rennie's harbour survey of 1805. (2)

The building was rectangular in plan with four storeys and a three storey extension on the western end. The southern walls of this extension were uncovered during the excavations; two successive wall footings built of mortared greensand with some flint. Although surface built the earliest wall had been carried down to a deeper level, where it cut through the infill of an earlier cellared building (building 46). The later wall clearly represented a later rebuild of the early wall.

A culvert, observed at several points along the south-eastern side of the site is likely to have been associated with Clarence House. It was a deep drainage culvert, set within a large construction trench. It was 0.7m wide and 0.65m high and was constructed of chalk blocks set in a hard pink lime mortar, with a dished base and a roof of large red bricks.

An 8m length of chalk block boundary wall was revealed running along the south-eastern side of Clarence Street, immediately to the south-east of the earlier series. This high level wall clearly represents a later replacement of the previous boundary walls and its change in position suggest a change in the width of the lane. The wall consisted of a single course of squared chalk blocks set in a pink lime mortar, very similar to that used in the culvert. It had been constructed without a foundation and lay upon the floor of building 50.

Three boundary walls located to the south west of the mansion, probably represent garden walls. Two contemporary walls were constructed from mortared greensand with some flint and brick. They were L shape in plan and ran parallel to each other. The inner wall appeared to form the north-west corner of a retaining wall for a sunken garden, 0.8m deep, terraced into the surface of the infilled East Brook Water. This was subsequently infilled with building rubble which included a number of fragments of kiln tile, similar to the examples uncovered within building 49. The purpose of the outer wall is less clear, possibly it bounded a 2.3-3.5m walkway around the sunken garden. This was later blocked by the insertion of a shallow rectangular chalk block lined tank. The third wall was surface built on a shallow foundation of flint cobbles with brick fragments. It appears to have been a later addition with the purpose of subdividing the open area between the main south western boundary wall of the garden and the wall surrounding the sunken garden. (3)

<1> Keith Parfitt, Barry Corke and John Cotter, 2006, Townwall Street, Dover: Excavations 1996 (Monograph). SKE31840.

<2> John Rennie, 1805, Plan of the Town and Harbour of Dover (Map). SKE31993.

<3> Keith Parfitt, Barry Corke and John Cotter, 2006, Townwall Street, Dover: Excavations 1996 (Monograph). SKE31840.