Many people call Ryomyong in Pyongyang a green street. Illumination as well as a cooling and heating system based on renewable energy have been introduced in every flat, the interior walls of which are finished with anion-emitting plastic wallpaper or paints. Planted on the entresols of high-rise and super-high-rise apartment blocks including the 70-storeyed one are trees and flowering shrubs. And various kinds of vegetables are cultivated in the hydroponic greenhouses on the roofs of many buildings including kindergartens and nurseries in the street.