Dalhousie Castle lies on the B704, 4 miles (6.5km) south of Dalkeith, on a promontory overlooking the River South Esk, south of its confluence with the Dalhousie Burn. The parkland extends down to Prestonholm House to the south, along Castle Dean Wood to Dalhousie Strip Wood on the west and from Cockpen Bridge along Dalhousie Burn to its confluence with the South Esk. The eastern boundary runs along Catholes Wood to the Old Manse.
The surrounding landscape is agricultural but has been extensively damaged by coal mining and mineral working in the vicinity of Newtongrange and Gorebridge. The immediate area is well wooded and the woodlands associated with the designed landscape do not make a particular contribution to the local scenery. No outlying features play a prominent part in the designed landscape.
The Castle lies in the centre of the policies at the northern end of the park. It stands above the river, detached from the surrounding woodlands on the east, and is linked to the surrounding landscape by a small finger of woodland to the south-west running along the river. Open parkland, now cultivated, extends north and west, and the river meadow, Anna Park, lies below to the south.
Evidence of the former extent of the designed landscape has been drawn primarily from the 1st edition OS map of 1854; there are known to be estate papers in the Scottish Record Office but these have not been reviewed for this study. Today the designed landscape extends to an area of about 892 acres (361ha).