This will be an amazing site and engineering feat if and when constructed.

The challenge was to design a vertical structure, on the island of Cotonduba, that in addition to serving as an observation tower would become a symbol of welcome to newcomers in Rio either by sea or by air once it had been host city to the 2016 Olympic Games.

Designed by RAFA firm headquartered in Zurich, Switzerland, it is called "Solar City Tower"; this structure has the potential to generate enough energy not only for the Olympic city, but also for part of the city of Rio.

Its design makes it store solar energy during the day; surplus energy produced is piped to pump sea water within the tower giving the effect of a waterfall outside. This water is reused simultaneously by turbines designed to produce energy during the night.

The tower also has an amphitheater, an auditorium, cafeteria and shops accessible on the ground floor; you can take an elevator to various observatories and a retractable platform for 'bungee jumping'.

From an e-mail