This Roof Will Grow on You

The great buildings of the 20th century may have been made of glass, but in the 21st century the boldest designs will be... grass. Italian architect Renzo Piano merged architecture with nature when he designed a green roof for the new California Academy of Sciences building in Golden Gate Park in San Francisco. The earthen roof is planted with more than more than 1.7 million plants from nine different native species.

^{Photo: Workers at the California Academy of Sciences prepare the roof for plantings. © David Paul Morris / Getty Images}