Sentence:  Morocco was in 1883-1884 the scene of important explorations by de Foucauld, a Frenchman who, disguised as a Jew, crossed and re-crossed the Atlas and supplied the first trustworthy information as to the <WSD>orography</WSD> of many parts of the chain. 
Meaning of the word marked with <WSD> tags:  the orographic features of a region