The use of mobile applications on smartphones has a vast potential to support learning in the field. However, all learning technologies should be properly designed. To this end, we adopt User-Centered Design (UCD) to design a mobile application, called GeoFARA (Geography Fieldwork Augmented Reality Application), for university geography fieldwork. This paper is about the conceptual design of GeoFARA based on its use and user requirements. The paper first establishes a review of selected existing mobile AR applications for outdoor use, in order to identify the innovative aspects and the improvements of GeoFARA. Thereafter, we present the results of use and user requirements derived from (1) an online survey of the current use of tools in undergraduate geography fieldwork, (2) a field experiment in which the use of paper maps and a mobile mapping tool were compared, (3) investigations during a human geography fieldwork, (4) post-fieldwork surveys among undergraduates from two universities, (5) our use case, and (6) a use scenario. Based on these requirements, a conceptual design of GeoFARA is provided in terms of technical specifications, main contents, functionalities, as well as user interactions and interfaces. This conceptual design will guide the future prototype development of GeoFARA.