Built in 1972 next to the Exxon Building in the Rockefeller Center Extension. The McGraw-Hill publishing company had studied the possibility of expanding to a new office building built above the Port Authority Bus Terminal expansion, then in planning stage, at 42nd Street -- next to the company's current Art Deco premises. Due to the questionable status of 42nd Street, the plan was dropped. The 205.5 m tall building has its piers, uniform within the Extension, clad in red granite. Around the west side of the 51-storey tower is a seven-storey base, behind which runs the landscaped through-block public passageway, necessitated by the city authorities for the Extension buildings. When McGraw-Hill relocated to Rockefeller Center, it occupied two-thirds of its new 167,300 m² namesake building.