Caves, cut into a cliff rather than built on the ground, provide an alternative approach to defining space. The most provocative of them provoke fundamental questions about the very nature of architecture—what it is and how it functions. This dissertation investigates how the architecture of the Mogao caves near Dunhuang—a major cave complex in northwest China built from the fourth to the fourteenth centuries—transformed a desert cliff site into a Pure Land, a Buddhist paradise on earth. Through analyzing five selected landmark caves, cave composites, and cave clusters at Mogao, this dissertation locates the architectural turn in new design and construction paradigms of the Tibetan (778–848) and the Guiyijun (848–1036) periods. The new architecture played critical roles in the history making and placemaking of Mogao by mediating between the past and present times and bridging actual and visionary places. Because it evolved from the particular site of Mogao and was paradigmatic in the Dunhuang-Anxi region, this mode of architecture is termed the Dunhuang style.The dissertation begins by investigating a special cave composite as a microhistory that epitomizes the architectural transformation of the Mogao cave complex. Known as the three-story pavilion, this composite comprises three decorated caves arranged vertically plus the famous Dunhuang library cave, all covered by a three-level timber façade. Chapter 1 reconstructs the process of the pavilion’s becoming, highlighting its continual redevelopment and reintegration throughout the ninth to eleventh century. The next four chapters contextualize the pavilion’s complex form and the changes in the architectural developments of the Mogao cave complex during the Guiyijun period. It examines how four new paradigms—synthesis of pictorial and spatial arts, competition for verticality, externalization of Pure Land imagery, and cave grouping—made the cave architecture more comprehensive and the Mogao site more wondrous. Chapter 2 investigates how a pagoda-themed cave could embrace multiple pagoda imageries that are conveyed through pictorial, plastic, and architectural mediums and that institute a ritual place endowed with miraculous forces. Chapter 3 demonstrates the leading role of the colossal-image caves and their multilevel porches in shaping the overall imagery of the Mogao complex as heavenly palaces of unparalleled height. Chapter 4 understands the sweeping refurbishments of the Mogao cliff of the tenth century as a new paradigm of Pure Land art, which integrated the interior and open-air murals and the timber-framed porches into a tangible image of the sacred realm. Chapter 5 discusses the key roles that the central-altar caves that were commissioned by the Guiyijun leaders played in shaping the old district of Mogao into an allusion to the future Buddha Maitreya’s Pure Land, the only Pure Land prophesied to appear in the mundane world.