Queen Mary's House was originally a 16th century bastle house, which had a first floor hall and an attic, above a vaulted basement. In the 16th and 17th century, the Ker family altered the bastle, when integrating it into a T-plan tower house. The main block is of three storeys and the a centrally projecting wing is of four storeys. There is a left-hand stair turret in the angle and a vault pend leads to the original entrance. Nearby is Jedburgh Castle and 2 miles north-west is Lanton Tower.