Floating leisure infrastructure represents an evolving frontier in architectural and engineering innovation, offering sustainable and adaptable solutions for waterfront developments. This chapter examines the design, construction, and implementation of the world’s largest floating infinity pool, developed for the Mandarin Oriental Lago di Como Hotel. The 600 m2 floating structure, featuring a 40 m infinity edge presented unique engineering and architectural challenges, requiring bespoke technical solutions to address stability, comfort and environmental integration. Drawing on historical precedents of floating leisure infrastructure, this chapter contextualises contemporary floating pools within a broader architectural lineage, tracing developments from early Victorian floating baths to modern floating leisure facilities. The project’s engineering solutions were informed by extensive hydrodynamic studies, including in-situ data collection and wave tank testing at Finland’s VTT Technical Research Centre. A catamaran-based structural system, damping plates and a precision-designed mooring system were deployed to enhance stability and mitigate motion-induced discomfort. The chapter also explores the complex integration of an infinity-edge pool into a floating platform, a feature that demanded innovative hydraulic and structural strategies to maintain aesthetic and functional performance. As floating leisure solutions gain prominence, they present a compelling model of sustainable waterfront development, balancing luxury, environmental considerations and engineering excellence.