This is Zawiya of Sidi Sabib - this is a religious complex in Kairouan which is the holiest site in Tunisia. It is the burial place of Abu Zama'a al-Balawi (also known as Sidi Sahib) who was Muhammad's Barber, it would seem apt that he was supposedly burial with three hairs from Muhammad's beard, which one assumes he trimmed at some point. This was the year 654. The buildings however are from 17th century.
This is the minaret
One of the inner courtyard with the fantastic arches