Extremely controversial when built, the Transamerica Pyramid has become a San Francisco landmark and one of the country's most recognizable skyscrapers. The design is counterintuitive from a practical and financial standpoint, since the most desirable upper floors have the least area. Yet the scheme works well for a building dominated by a single tenant and illustrates the ability of modern structures to create strong corporate identities for their owners. The pyramid form was chosen as a way to maximize building height under planning regulations, and as a strategy to allow more light to reach the street level where the building rests on concrete clad steel piers forming a loggia between the sidewalk and lobby. Below the aluminum sheathed point, cladding panels of glass and precast concrete complete the exterior and demonstrate the ascendancy of exposed concrete in modern building construction by the early 1970s.