Designated on 7th January 1977. A small and compact Conservation Area consisting of two mid nineteenth century formal terraces, a large prominent Roman Catholic Church and presbytery and a modern church hall. When built, this area was suburban, being peripheral to the built-up area of the town and some distance away from the industrial riverside. The site has solid rock just below the surface and is well drained. Walker Terrace (HER 8306) was built 1842-3. Regent Street (HER 8298) was built in 1852-62. Queen's Terrace, which faced Regent Terrace, has been demolished. The church of St. Joseph (HER 8277), linked presbytery and schools (demolished) were built in 1859. The church hall is a modern brown building and is flat roofed with steel-framed vertical slit windows. It is out of keeping with the Conservation Area.

Shown on Ordnance Survey first edition (1850).

Single long terraces, separated by a back lane with long gardens to the front. Built of pale colliery brick with Welsh slate roofs. Window openings have been changed, there are many rear extensions, porches and conservatories.

Shown on Ordnance Survey first edition (1850) up to fifth edition (c.1960).

The only surviving building within the colliery yard. Built of banded brick with banded asbestos roof tiles.

Laid out within the former Colliery yard (HER 6379).

Shown on Ordnance Survey third edition of 1919.

The board school and school house (HER 12036) were built in 1875. A typical, though attractive tall single-storey stone and slate Board School. It is symmetrical with wings projecting forward. Windows are mullioned and transomed. Some are half-dormers. There is a central cupola housing the school bell and capped by an ogee roof.

These are the oldest buildings in Marley Hill and form a much altered agricultural group of stone and slate. They are shown on the Ordnance Survey first edition map of 1850 as two ranges of buildings arranged in an approximate T-shape and labelled 'Sandy Gate'. They are not labelled as a farm on this or on subsequent editions, but the small cultivated areas shown to the west and south indicate some agricultural activity.
There is supporting documentary evidence that Sandy Gate was a farmstead in the early 19th century. Thomas Burnip is listed in the Durham North Pollbook 1832 for a Parliamentary Election as resident at Sandy Gate in Whickham, his qualification to vote being 'Farm'. Sandy Gate is also shown on the tithe map for Whickham township (ref. DDR/EA/TTH/1/251), dated 1842.
The 1841 census lists the occupants of Sandy Gate in the sub district of Whickham as Thomas Hutchinson, a farmer, his wife Hannah, eight children, and three others including an agricultural labourer. By the time of the 1851 census the Hutchinsons had left, and Sandy Gate was being used to house the Greener, Thompson and Forster families, who worked in the colliery.

Three terraces of red brick houses of late C19/early C20 date, aligned at right angles to Stella Road.