The cultures of the endangered Modern South Arabian Language (MSAL)-speaking people of Southern Arabia and the natural environment in which they developed are facing serious threats of extinction due, on the one hand, to fast social changes such as urbanisation and Arabization, and on the other, by ecologically unsustainable human activity (building of roads and infrastructures, increasing tourism) and climate change, which brings desertification and catastrophic events. Within this scenario, the loss of autochthonous knowledge concerning the traditional relationship between man and landscape has strongly negative effects on the local culture. This project aims at documenting and analysing the toponymic and orientation systems applied by native MSAL speakers to describe and refer to the environment in which they live: the main goals of the project are to portray the ontology of the MSAL landscape description system, preserve the memory of this endangered intangible cultural heritage, and foster the maintenance of and interest in traditional knowledge.