This concise review posits the urgent need for conserving the natural diversity of mountain environments by envisioning mountains as a global natural heritage. Mountains are recognized as cradles of biodiversity and for their important ecosystem services. Mountains also constitute the second most popular outdoor destination category at the global level after islands and beaches. However, in the current age of accelerating global environmental change, mountain systems face unprecedented change in their ecological characteristics, and consequent effects will extend to the millions who depend directly on ecosystem services from mountains. Moreover, growing tourism is putting fragile mountain ecosystems under increasing stress. This situation requires scientists and mountain area management stakeholders to come together in order to protect mountains as a global heritage. By underlining the salient natural diversity characteristics of mountains and their relevance for understanding global environmental change, this critical review argues that it is important to appreciate both biotic and abiotic diversity features of mountains in order to create a notion of mountains as a shared heritage for humanity. Accordingly, the development of soft infrastructure that can communicate the essence of mountain destinations and a committed network of scientists and tourism scholars working together at the global level are required for safeguarding this shared heritage.