Ariau amazon towers hotel in manaus, brazil, is the world's largest commercial tree house. Amazingly,ariau's towers are built at the level of the rainforest treetops , about 72 feet (22 meters) in the air.The towers are linked together by four miles (six kilometers) of wooden catwalks. This very unusual sitting gives guests the unique opportunity to experience the plant and animal life of the rainforest canopy while leaving the rainforest's ecosystem undisturbed.