Residents in Guiyang city, south-west China, thought they were imagining things when they saw a massive waterfall cascading out of a high-rise building in the middle of the street.The 108-metre-tall (350ft) fall is indeed a part of the towering Liebian Building, located at a public plaza in the city's central business district.A large tank is installed at the foot of the 121-meter-tall (397ft) skyscraper, where four 185-kilowatt pumps would lift the water to the top of the fall.