Kapoor's earliest public commissions include the "Cast Iron Mountain" at the Tachikawa Art Project in Japan, as well as an untitled 1995 piece installed at Toronto's Simcoe Place resembling mountain peaks. In 2001, "Sky Mirror", a large mirror piece that reflects the sky and surroundings, was commissioned for a site outside the Nottingham Playhouse. Since 2006, "Cloud Gate" (colloquially known as "the Bean"), a 110-ton stainless steel sculpture with a mirror finish, has been permanently installed in Millennium Park in Chicago. Viewers are able to walk beneath the sculpture and look up into an "omphalos" or navel above them.