Adamorobe, a small Akan village in Ghana, has an unusually high incidence of hereditary deafness. As a result, a sign language came into being, Adamorobe Sign Language (AdaSL), which is unrelated to any other sign language described so far and is assumed to be about 200 years old. The present study describes selected aspects of AdaSL, notably phonology, lexicon, the expression of size and shape and the encoding of motion events. A comparison of these aspects with descriptions of other sign languages reveals interesting cross-linguistic differences in the use of iconicity as well as in the use of space and classifier constructions. Data were collected during three periods of fieldwork of nine months in total. Moreover, this study considers to what extent the social setting may influence the development of structural features in sign languages. This investigation nuances the impact the visual-spatial modality has on sign language structure. The book is of interest to scholars of sign linguistics, African linguistics, as well as contact linguistics and Deaf studies.