These 1920s offices appear to have replaced a building shown on the Second Edition Ordnance Survey map, but may in fact have incorporated it.

The Directors House is shown on the Third Edition Ordnance Survey map. It is a detached 3 bedroom cottage style house typical of the period, built in brick with render to the second storey and stone lintels and cills to the windows.

Nursery Cottage is shown on the First Edition Ordnance Survey map as a linear range of buildings oriented east-west on the south side of Castles Farm Road. Later editions show glasshouses attached to the buildings to the south and east. The cottage is built of stone with render to the second storey and has had numerous alterations.

The reservoir was built during the early decades of the 20th century to store and supply ground water via the Leechmere Road Pumping Station to the Hendon Paper Mill (HER 16627). This reservoir was part of a series which supplied the paper mill with fresh water. Cartographic evidence indicates a construction date between 1914 and 1940 with a tighter date range of 1923 - 1939 coinciding with rebuilding of the mill during this period.

A series of gullies were excavated as part of a larger excavation. One contained a flint fragment and a charred heather twig returned a radiocarbon date of cal AD 260-430.The gullies were tentatively interpreted as a rectilinear enclosure.
Excavation was undertaken in 2021 and post-excavation analysis was undertaken in 2023 (event 5467 report 2023/34).

A series of ditches and gullies were excavated as part of a larger excavation. A boundary ditch aligned approximately northwest-southeast and continuing to the northwest was identified initially by geophysical survey and trial trenching. The palaeoenvironmental assemblage indicated a late prehistoric or Romano-British date and a fragment of birch charcoal gave a radiocarbon date of 390-200 cal BC. Another ditch intersected with it and there were a series of gullies to the northwest, one of which produced a piece of alder charcoal which gave a radiocarbon date of 540-390 cal BC. An oval
enclosure ditch in the northwestern part of the site was only partially excavated in a trial trench.
Excavation was undertaken in 2021 and post-excavation analysis was undertaken in 2023 (event 5467 report 2023/34).

Two pits dated to the Bronze Age were excavated as part of a larger excavation. One contained crumbs of probable prehistoric pottery and three flints, and a charred hazel nutshell gave a radiocarbon date of 2140-1940 cal BC. The other gave a radiocarbon date of 1430-1290 cal BC from a charred barley grain.
Excavation was undertaken in 2021 and post-excavation analysis was undertaken in 2023 (event 5467 report 2023/34).

This structure was subject to historic building recording in 2021 prior to the demolition of Sunderland Civic Centre (event 5462 report 2022/88). It was constructed in shuttered concrete during the main works for the Civic Centre in order to house the NER Penshaw Branch which dated to 1852 (HER2659). The easternmost section was constructed of coursed limestone masonry. The line originally served the South Dock (HER2874), and here ran through a cutting: it was closed in 1984. The tunnel was c187 m long and had four pedestrian refuges on each side.

This structure was subject to historic building recording in 2021 prior to the demolition of Sunderland Civic Centre (event 5462 report 2022/88). It was constructed as part of the Sunderland Civic Centre as a sub-basement, but was adapted as a nuclear bunker in the 1970s. It was a subterranean structure 32 m by 7 m made of concrete shuttering and close-set steel sheets, with an entrance in the northeast face of the northernmost hexagon of the Civic Centre complex. It was equipped with a ventilation system and toilets.

Grange Farm is shown on the Ordnance Survey First Edition map as a linear range of buildings on the west side of Stockton Road, just south of the point where it crosses the line of the NER Penshaw Branch (HER2659). The southernmost building in the range is labelled as a 'Warehouse' on the 1:500 town plan, suggesting that the agricultural function of the farm was reducing. To the southeast lay 'The Grange' and the attached 'Grange School'. In the mid 19th century the area was gradually being developed for housing and Grange Farm had gone by the late 19th century.