 The hotel opened on May 25, 1964, as the San Francisco Hilton.Built at a cost of $29 million and designed by noted architect William B. Tabler, the innovative 18-story, 1200-room structure was known as a "motel within a hotel" due to a design featuring a series of ramps in the middle of the building, allowing guests to drive their cars directly to seven of the hotel's lower floors and park adjacent to their room.Tabler's design also employed a checkerboard facade of windows and decorative panels to disguise the building's earthquake bracing.