Opened in 1964, the 18-story, 1200-room original building was known as a "motel within a hotel", allowing guests to park directly next to their upper-story rooms.

[7] Filling an entire city block, it remains one of the tallest structures representing Brutalist architecture, though it has been extensively altered since its construction.

Built at a cost of $29 million[1] and designed by architect William B. Tabler, the 18-story, 1200-room structure was known as a motel within a hotel[7] 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.

[11] Tabler's design also employed a checkerboard facade of windows and decorative panels to disguise the building's earthquake bracing.

It also had one of the world's largest ballrooms at the time,[citation needed] which was reached by escalators from the lobby to the floor below, handling a banquet of 2000 or a meeting for 3000.

The hotel was built by Cahill Brothers, Inc. in San Francisco, with David T. Williams, Inc. of New York handled the decorating.

[10] In 2023, Park Hotels & Resorts (an investment trust spun off from Hilton Worldwide in 2017) surrendered the building and the nearby Parc 55 San Francisco to its lender JPMorgan Chase, citing San Francisco's "record high office vacancy; concerns over street conditions; lower return to office than peer cities; and a weaker than expected citywide convention calendar.