The book chapter explores the accessibility conditions in the hill settlements and their effects on the functional independence of the older adult populations in performing daily life activities, shedding light on the challenges they encounter in the out-of-home environments and creating opportunities for sustainable mobility solutions. Hill settlements, characterized by their rugged terrain, steep slopes, and often remote locations, pose numerous obstacles to mobility, particularly for an ageing population. In the wake of population ageing, urbanization, and migration among younger adults for employment, the paper attempts to address the need for an accessible built environment that reduces mobility impairments and supports older adult populations to experience higher functional abilities, thereby enhancing life satisfaction in neighbourhoods located in hills. The chapter begins by highlighting population ageing as a demographic future trend, and subsequently delves into the myriad accessibility challenges posed by the geographical constraints, inadequate infrastructure, and inadequacy of design standards prevalent in hill settlements which hampers the independent out-of-home mobility among the older adult populations. In response to these challenges, the chapter exhibits various sustainable and age-friendly space planning and mobility solutions, outlining specific design, and planning guidelines for building enabling-environments for the older adult population in hill settlements. Moreover, the chapter envisions a future where aligning these efforts with global sustainable development goals will significantly enhance inclusiveness and well-being among the older adults residing in hill settlements.