The monument consists of the ruins of Gamelshiel Castle, a small towerhouse of 16th century date.
The extant upstanding portions consist of the E and W walls. These
are constructed in narrow-coursed whinstone. The structure is
externally 7.4m wide over walls 1.3m thick and 6-7m high. Its
original length was about 16m. Part of the NE angle remains. The basement appears to have been vaulted. The area between the walls is filled with a turf-covered mass of fallen rubble.
The area to be scheduled is triangular and measures a maximum of 50m
N-S by 55m E-W, to include the castle and a surrounding portion of
land where buried features relating to the castle are likely to
survive. The N boundary is defined by the Hall Burn, the E limit is defined by a track, which is excluded from the scheduled area. The
area is shown in red on the accompanying map.