Montology is a transdisciplinary field of research committed to the sustainable development of the world’s mountain regions. In this context, cities in mountains have been little investigated. The aim of this chapter is to advance a montological perspective on the study of cities in mountains. One key to understanding mountain cities is their specific geographic position within natural and cultural space and their topographic location. Related to this are factors such as accessibility and the reach of central-place goods and services. Locational factors are subject to continual change in the course of a city’s development. With recent technological advances in mobility (motorization, air traffic, cable cars) and in modern communication (internet) cities have lost some of their significance. Location is also linked to numerous risk factors (earthquakes, volcanic activity, mass movements, floods), which are exacerbated by climate change. Mountain cities, more than centers in foothills and plains, must invest more in securing their living environment and in adaptating to climate change and natural hazards. There are additional societal and/or cultural challenges for the sustainable development of mountain cities (peri- and post-suburbanization, tourism, immigration, etc.). A transdisciplinary human–environment approach is needed to meet these challenges and ensure sustainability, and it involves experts, decision-makers and the population at large. It should focus on issues which have received little attention in research to date.