High Quality Content by WIKIPEDIA articles! The Guardian Building is a skyscraper at 500 Griswold Street in the downtown of the city of Detroit, in the state of Michigan, in the United States of America. The Guardian is a class-A office building owned by Wayne County, Michigan and serves as its headquarters. Built in 1928 and finished in 1929, the building was originally called the Union Trust Building and is a bold example of Art Deco architecture, including art moderne designs. At the top of the Guardian Building`s spire is a large American Flag, complementing the four smaller flags atop nearby 150 West Jefferson. The building has undergone recent award-winning renovations. It was designated a National Historic Landmark on June 29, 1989, and it is part of the Detroit Financial District. The Guardian building includes retail and a tourist gift shop.