Before revision: Sustainable Development of Urban Underground Space (UUS) As a step towards achieving the Unites Nations' SDGs (in particular Goal 11: Make cities and human settlements inclusive, safe, resilient and sustainable), urban cities in developed economies of the world are increasingly looking "downwards" rather than expanding limited land resources at the surface.
After revision: Sustainable Development of Urban Underground Space (UUS) As a step towards achieving the United Nations' SDGs (in particular Goal 11: Make cities and human settlements inclusive, safe, resilient and sustainable), urban cities in developed economies of the world are increasingly looking "downwards" rather than expanding limited land resources at the surface.