The Friday Mosque in the oasis town of Chinguetti in Mauritania was built in the thirteenth or fourteenth century. The walls of sanctuary are built of stone, enclosing a courtyard. The square minaret towers over the town, and is built of dry yellow and rose-colored stone without mortar. It is capped by four pedestals, each topped with a stone ostrich egg. A fifth egg sits in the center of the roof of the minaret, defines the axis towards Mecca when seen from the west.

The mosque is constantly threatened by the shifting sand dunes and desertification. In the 1970s it was restored through a UNESCO effort

Image: World Monuments Watch http://wmf.org/resources/sitepages/mauritania_chinguetti_mosque.html

Reference: ArchNet http://archnet.org/library/sites/one-site.jsp?site_id=7728