medieval house, another Marinid-era house (probably 14th century), known as Dar Sfairia or Dar al-Fasiyin, was studied by Henri Terrasse and Boris Maslow, of similar form but more modest. It too was demolished in the late 20th century, however several other houses possibly dating to the Marinid era or to the Saadian era have been studied by Jacques Revault, Lucien Golvin and Ali Amahan in their study of the houses of Fes, all featuring variations on the same overall form as the house studied by Alfred Bel: a central square courtyard surrounded by rooms which opened through tall archway doors, sometimes with windows above the ground floor doorways, and often behind a two story gallery. While most houses have a simpler arrangement of one pillar at every corner of the gallery, larger mansions such as Dar Lazreq (owned by the Lazreq family since the 19th century) and Dar Demana (built by the Ouazzani family) have clusters of three pillars at every corner (for twelve pillars in total), repeating the motif of a large central opening flanked by smaller arches on every side of the gallery. Wooden lintels forming corbelled arches in the galleries is a common feature throughout, sometimes carved with vegetal or epigraphic decoration and sometimes supported by ornate stucco corbels. Dar Lazreq, which likely dates to the 15th or 16th century, features the same kind of sebka-based stucco decoration in the spaces above the small side arches of its courtyard gallery. Dar Demana, which dates in style to the Marinid period but may have been founded earlier, is distinguished further by a short lookout tower (a menzeh) on its roof terrace, allowing its owners to enjoy a better view of the city – a feature present in many mansions in both Fes and Marrakesh. It is also adjoined by a separate riad garden, a feature which was not previously common in the architecture of Fes. Both Dar Demana and Dar Lazreq were recently restored in the 2010s. The oldest surviving houses in Marrakesh date from the 16th or early 17th century during the Saadian period. A number of such houses still stand today in various states of preservation. These include the Dar Cherifa (formerly known as Dar Ijimi), the Dar al-Mas'udiyyin (partly ruined), and the Dar al-Masluhiyyin (known also as Ksour Agafay). The Mouassine Museum also contains an example of a restored Saadian-era douiria, or upper-floor guest apartment.