Land-use frontiers, such as agriculture expanding into forests, remain a major driver of biodiversity loss, and often lead to conservation responses. To better understand the geographies of conservation, connecting conservation with tools used widely in Land System Science – particularly the frontier concept – allows assessing the patterns, actors, and drivers of conservation. We propose that land conservation can be analysed through three different perspectives. First, conservation can be framed as efforts to slow or stop other frontiers. Second, the expansion of conservation could itself be described as a frontier process, similarly leading to institutional and cultural reorganization, and sometimes conflicts (e.g. green grabbing). Third, frontiers can be seen as spaces where multiple land uses, including conservation, interact. Analysing conservation through these perspectives could be particularly powerful to thoroughly consider the social-ecological contexts in which conservation happens, and thus to bridge the disciplines of Land System Science and Conservation Science.