A high income per inhabitant and the increase in lifespan of populations in developed countries are generally admitted to be the main pillars of senior tourism. Admitting that the increase in lifespan is partly conditioned by social and environmental factors that are beneficial to human longevity, than if tourism is one such factor, it will contribute to a virtuous cycle of interaction between the self maintenance of this longevity and the development of senior tourism. Three clusters can be identified: convivialists, spiritualists and innovators, which differ significantly in social demography, holiday habits and in their reasons to come to Lisbon.