The Serengeti National Park, Tanzania, is home to a vast number of species and forms part of one of the last great migratory systems that remains intact.
More than 1,500 ground-rumbling, lava spewing — and stunning — volcanoes dot the planet, changing their surroundings and renewing resources as they go.
Rio-based architecture and design group RAFAA have released plans for a self-sustaining tower. Part of the 2016 Olympic plan, the tower will generate enough energy to power the athletes village.