Note on the Seminary: The keep serves as the refectory. There is a large temple with a tower in the center of the courtyard, dormitories and classrooms with a cloister walk on the south and east, and gatehouse and domestic offices on the west side. The precinct wall roughly follows the line of the original castle curtain wall, but is no longer battlemented except on the north and east sides facing the rivers. The seminary occupies an island between the River Lin and Lorig Burn, with a wet moat cutting off the promontory. There is a watergate with a small dock on the east side. Both gatehouses date from the reconstruction period but occupy the sites of the originals. Ruins of the fortress are to the south; the old castle on its island had become an outwork.
The original keep (c. 1480) consisted basically of the vaulted cellars and the Great Hall, with the round tower being added about fifty years later. In 1600 the square entrance tower with its gun loops and the spiral stair towers were constructed and the interior remodelled; the kitchen and other offices were originally in what is now the 'Long Green'. Entry is in the reentrant angle of the tower, which contains the porter's lodge and a single flight stairway; the next floor contains a guard room, or waiting area, and above that the two-storied quadripartite-vaulted chapel. The kitchen and three vaulted cellars are accessed from a ground-level passageway at the end of which is the slop drain and garderobe pit; the kitchen has a well and a large fireplace, and a single-flight spiral stair up to the serving room. The two-storied great hall is a fine room with a hammerbeam roof, oak panelling, and an arcade with a gallery above. At one end are the servery and butler's pantry, at the other the fireplace and the main stair to the upper floors. The lavatory is at the end of the arcade. Chapter House (priests' meeting room) takes up two stories of the round tower (which has square rooms above the ground floor) and has a quardripartite vault like the chapel in the other tower. Over the chapter house is the audience chamber (High Priest's office) and the observatory -- star-watching for astrological purposes is a major activity in this religion. The west wing contains the chantry, scriptorium, and chief Sacristan's quarters (he is also General Secretary and though not titular head de facto runs the place) and has its own spiral stair. Apart from a small terrace or wall walk on the north, the keep is not battlemented -- one of the 'peace' conditions imposed during its reconstruction.