The Cadillac Tower is one of the most imposing skyscrapers in downtown Detroit, a 40-story white giant standing over Cadillac Square and Campus Martius.

Work began in 1926. The building, designed by the firm Bonnah & Chaffee, has been in continuous use ever since.

The Cadillac Tower was the brainchild and namesake of John J. Barlum, who funded its construction. Barlum was president of the Barlum Realty Co. and the New Cadillac Development Co. He made his money initially through his father's meat-packing business. He and his brothers, Thomas and Louis, would invest their wealth in real estate, adding to their fortunes.

The first piece of steel to reach the roof was laid May 9, 1927, and the rest of the steel was in place a few weeks later. Amazingly, the building was formally opened just a few months later, on Nov. 9, 1927.

Though the interior of the building has lost almost all of its original splendor and charm, its exterior remains almost unchanged.

The building is designed in the Late Gothic Revival style and sheathed in terra cotta, with golden accents -- also in terra cotta -- on the top five floors. The windows feature a Gothic arch, and the roofline is dotted with newels and cone-shaped spires on the corners.

A common question is why the side of the building facing Campus Martius is nothing but a giant brick wall for 35 stories. The answer lies in its fallen former neighbor, the Cadillac Square Building, which stood next door. When the Cadillac Tower opened, there was no point in having windows looking into another structure's windows.

More on this building coming soon.