Sven Zacek / Tallinn city wall and old town, UNESCO World Heritage Site. New town and Lake Ulemiste beyond. In evening light. Harjumaa, Estonia. May 2011.

Juan Carlos Munoz / Roof of Villa El Capricho de Gaudi designed by Antoni Gaudi, built in 1883-1885, Comillas, Cantabria, Spain. May 2018.

Staffan Widstrand / Wild Wonders of China / Temple roof at the Xuan Kong Si, or Hanging Temple, 1800 years old, with paintings of birds, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Staffan Widstrand / Wild Wonders of China / Details from the Yong An Si temple, now a museum, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Staffan Widstrand / Wild Wonders of China / Details from the Yong An Si temple, now a museum, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Staffan Widstrand / Wild Wonders of China / Tiger face in roof tiles. Details from the Taoist Bai Long Wang Miao, White Dragon King Temple, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Staffan Widstrand / Wild Wonders of China / Tiger or owl faces in roof tiles. Details from the Yong An Si temple, now a museum, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Staffan Widstrand / Wild Wonders of China / Chinese beautiful rosefinch (Carpodacus davidianus) perched on an old statue in Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Eladio Fernandez / Ekman's silver palm (Copernicia ekmanii) in coastal settlement, Hispaniola. August 2014.

Staffan Widstrand / Wild Wonders of China / View of Tibetan Lamaist Songtsam Monastery houses, Shangri-La, Yunnan, China, October 2017.

Ashley Cooper / The Alan Turing building, which has rooftop solar panels to generate around 41 Megawatt hours of clean electricity per year. Manchester, England, UK. November 2011

Ashley Cooper / A tiny solar photo voltaic panel on a rooftop in Kathmandu, big enough to power a couple of lights in the house below, Nepal. January 2013