The New York City Landmarks Preservation Commission (LPC) in late July voted to designate the AT&T Corporate Headquarters Building as a landmark. The building, later known as Sony Plaza and now 550 Madison Avenue, is an icon of the Manhattan skyline and of postmodern architecture.

550 Madison Avenue is now a designated landmark.“This is the building that established postmodernism as a legitimate architectural movement. It deserves to be preserved for future generations," said Landmarks Preservation Commission Vice Chair Frederick Bland.

The AT&T Corporate Headquarters Building, built between 1978 and 1984 was designed by Philip Johnson and John Burgee as a statement building with powerful, dramatic forms drawing on classical references. It was the world’s first skyscraper associated with this new style.

Soaring entrance to 550 Madison Avenue. The tower was featured in the movie "Wall Street", both as general office space and as the office of Gordon Gekko, played by Michael Douglas.

The so-called "Chippendale" pediment marked a turning point in architecture.

Located on Madison Avenue between East 55th and 56th Streets, the 37-story office tower is clad with pinkish-gray granite and crowned by a colossal broken pediment, a feature that sets it apart from other skyscrapers in midtown. At street level, its entrance is flanked by groups of flat arches that originally opened to twin arcades beneath the tower.

The tower was purchased by the Olayan Group and Chelsfield for $1.4 billion in 2016.

A movement to protect the building began in 2017 when the new owners revealed plans to renovate the base of the tower. The plan from Snøhetta would strip the pink granite from the 110-foot (33.5-meter) arch and loggias at the tower’s base and wrap it in glass. Critics said the proposal would have unbalanced the three-part arrangement between oversized openings at the base, in the central tower, and through the ornamental broken pediment at the skyline.