via rafaa.ch
Breathtaking and energy-conscious, this Olympic waterfall tower proposal for the Rio 2016 Olympics would employ solar-power to pump water and generate electricity for the city of Rio. It includes public spaces and an elevator to the observation deck at the top which provides a 360° view and a glass sky walk over water.
To top it off: a bungee-jumping platform.
Credit: RAFAA architecture & design, Switzerland