One key issue that has not been critically examined in African archaeology is what constitutes ‘archaeological sites’ archaeologists visit to survey and excavate, supplementing data from documents and oral histories. Archaeologists continue to perceive ‘archaeological sites’ as locales that contain archaeological signatures for historical events and processes, including artefacts, ecofacts and features. Non-artefactual yet cultural phenomena such as trees, forests, hills and outcrops are rarely considered as material culture. Consequently, some interpretations of ‘archaeological sites’ and material remains at such sites do not fit into conventional ways of conceptualizing history. This project funded by the Gerda Henkel Foundation, African Humanities Program and the University of Dar es Salaam, seeks to go beyond conventional thinking to focus on tree species that overtime assumes monumental sizes, a phenomenon that also occurs with Ficus species elsewhere in Africa. We investigate interactions of local communities with baobab trees (Adansonia digitata) from the remote past to modern times. This project’s thesis is that as they grow, some trees become ‘monumental’ or ‘living archaeological substances’ and are markers for deep-time spirituality as well as heritage identity.