Franco-Brazilian firm Triptyque Architecture has unveiled an ambitious plan to convert the long-neglected Minhocão viaduct undersection into a vibrant public space covered in suspended plants. Working with landscape architect Guil Blanche, the architects plan to hang oxygen-heavy plants over three kilometers of the elevated section to filter 20 percent of CO2 emissions. The Minhocão viaduct was built in 1971 when São Paulo was in a period of rapid growth.