Levitated Mass by artist Michael Heizer is the latest project at LACMA. On December 8, 2011, this 340-ton boulder, 21.5 feet (6.6 m) wide and 21.5 feet (6.6 m) in height, was ready to leave its quarry in Riverside County, after months of postponements.[82] It sits atop the 456-foot-long trench which allows people to walk under and around the massive rock.