Steel-frame, twenty-four-story building faced in limestone (1920-22) – Albert Kahn, Inc., architect. Designed by Wirt Rowland, chief designer for Albert Kahn, the building is similar in appearance to the former General Motors Building (now called Cadillac Place) from the same time period. The building's plan is shaped to fit in a contorted site that zigzags through the middle of its block, emerging on East Congress' north side at the Bates intersection behind the Vinton Building (1st and 2nd photos below). It was constructed as two units: the Rowland-designed unit 1 is at the corner of Woodward and Cadillac Square, and occupies the same footprint as the original Hotel Pontchartrain, while unit 2 attaches to the end of the original building and continues on a snake-like path to Congress Street. The facades fronting on Woodward and Cadillac Square at the building's north end are sheathed in grey granite at the street-level base and in limestone above, while other facades are finished in buff brick. The three facades facing Woodward and Cadillac Square display massive Corinthian porticos in antis rising from above the street level up to the fifth-floor level (3rd through 5th photos below) – the porticos on the Cadillac Square and corner Woodward elevations fronting an arched-ceiling banking room, at the time, one of the five largest in the country. The Corinthian pillars are modelled on the Temple of Castor and Pollux.
Above the porticos paired windows rise in vertical banks between broad and shallow piers up to a three-story high zone where, below a final story, metal panels replace the limestone spandrels. At the twenty-fourth (attic) floor, the window pairs are separated by decorative details, and there are cartouches marking the ends of each facade. An overscaled classical cornice with modillions and an acroteria band along the roofline have been removed. A portion of the building is constructed over a parking garage that faces Bates Street and East Congress Street. Above the parking garage is office space. The roof is flat. The first floor of the building contains retail store space, while the upper stories were designed for a bank tenant as well as commercial offices. The ground floor lobby features an interesting ceiling decoration (3rd and 4th photos below).
Photographed from Randolph Street, the building displays a nice fire escape on a nearly-featureless facade. There was apparently a pre-existing building next door (where there are no windows), but I don't know what it was, or when it was demolished.
The First National Bank was established in 1863, shortly after the 1862 passage of the National Banking Act. A Second National Bank, founded shortly after First, with leading Detroit businessmen such as Christian H. Buhl, Eber Brock Ward, and James F. Joy as directors, merged with First National in 1914 as the First and Old Detroit National Bank. The bank occupied its new quarters in February 1922, then shortening its name to First National Bank. The bank went into receivership in 1933.
More photos and more description of this building can be found at HistoricDetroit.org.