In a dystopic scenario of the nearby future, the average surface temperature and the sea level rise. Fresh water stocks are in shortage, energy blackouts are often and the social cohesion bursts. In a spiral direction of history, the cities turn to states once again and fortified megastructures emerge in the urban landscape. The “H2O Tower” has been desinged as a quasi autonomus community building with a lot of open spaces for public use. At the top of the tower there is a conical formation that gathers the rain water in a lake. The water after filtering, it is stored beneath, in a transparent cylindical tank. The tank has a triple function, it acts as a gigantic solar bottle bulb, a thermal storage mass and a tuned mass dumper. Right below is the atrium with the main "square" that hosts the life of the tower. The capsules are suspended between the rings in an alterability (plug in) logic and remain protected from the excess sun heat.