Also known as 175 Park Avenue, the Grand Central Tower was Breuer's most controversial project. In 1967, the Penn Central Railroad Group, which owned Grand Central Station, approached Breuer’s office to design a large tower meant to solve a shortage of office space in New York City and to make use of valuable air rights above the station. The tower was envisioned by the client as “a companion” to the nearby Pan-Am Tower (now Met-Life Building), designed by a team of architects that included Breuer’s mentor, Walter Gropius. Breuer and Beckhard’s first proposal floated 55 stories of cast stone and granite above the beloved, neoclassical facade of Grand Central. Both this first design (Project I) and later ones that would have demolished the station to make way for vertical or sloping legs to support the bulk of the tower (Projects IIa and IIb) were soundly rejected by the Landmarks Preservation Commission and so never built.