This thesis deals with the preservation and renovation of earthen architecture under UNESCO protection. Three world heritage sites are examined in detail: Aït-Ben-Haddou in Morocco, the Tulou in Fujian, China and the Takienta in Koutammakou, Togo. The aim is to find out how the sites and their inhabitants are affected by UNESCO protection and whether their usage changes after being set on the list of protected heritage. Furthermore, the threats to listed earthen monuments are investigated. In addition, the specific qualities of clay as a building material with its advantages and disadvantages as well as difficulties in the renovation of earthen heritage are discussed. My hands-on experience gathered at a workshop in Asslim, Morocco, is also taken into account. The three analysed World Cultural Heritage sites are compared in terms of their building technique, their building type, and their role as world heritage.