Below the tomb of Sidi Bu Madyan, at the lowest point of the complex, are the remains of a small palace that probably date to the same period as the mosque and madrasa, the "Dar al-Soltan," so named because it is believed to have been where the Sultan stayed during visits to 'Ubbad.  The palace, as described and illustrated by William and George Marçias, was not large, but featured at least two partially covered patios, arcades, water that flowed into and out of latrines and washbasins through walls and underground, and numerous rooms.[1]  Though the palace was abandoned after the fall of the Marinid dynasty and is in ruins, some of the fine decoration is still visible today.[2]

Notes:
[1] Marçias, 266-269
[2] Nomination to the World Heritage List.  p .4

Sources: