Gasr Banat or Gasr Isawi is an archaeological site near Bani Walid in Libya[1] and the location of an Ancient Roman centenarium or "perched" oppidum.

[5] Evidence from pottery found around the site suggests the date of construction was in the third century CE.

[2] The centenarium has a striking resemblance to one in Gherait esh-Shergia north of Wadi Nefud.

There is an ancient temple-type mausoleum dating to the same period as the centenarium in the valley, which contains a burial chamber decorated with fish.

However, regardless of the fallen walls the centenarium remained to be in a fairly good condition.