How to use a rooftop of a building

A series of photographs posted in the forum of China Daily showed some interesting uses of building rooftops in various parts of the world.

From infinity pools on top of a hotel in Singapore to an estate of villas on top of a shopping mall in China, some of the uses seemed like pretty good ideas for space-saving in built-up urban areas.

There are also some with environmental uses such as vegetable gardens, and for the health-conscious, a running track on top of a primary school.