Hoddom Castle was built by Sir John Maxwell of Terregles as part of a line of defensive structures completed by him in the 1560s. The lands of Hoddom were originally part of the Herries barony but did not form part of that which he got with his bride Agnes Herries and the lands had to be bought from her sister Catherine, wife of Alexander Stewart of Garlies.
The original structure was four storeys and a garret built on a 'L' plan. The stair tower reached up a further level to form a caphouse. The walls at the ground level are between nine and fifteen feet thick and rise to seventy-five feet at the wall walk. The basement has seven gun slots with another two at the bottom of the wheel stair. The fourth floor also has a number of downward angled shot holes. The castle stood in the northern corner of a four-sided courtyard, which had round towers of two stories at each of the other three angles.
The gate was originally in the north wall beside the tower. Being one of the last great towers built in the borders Hoddom didn't see a great deal of action. It was reportedly "thrown down" on two occasions but these were undoubtedly the exaggerated reports of English invaders. The castle appears not to have been built as a residence, but more likely as a barracks for troopers to defend the border.