Constructed in the late 1800s, Old St. Mary's Church is an incredible structure located in the Greektown Historic District of downtown Detroit, Michigan. Defined by its red brick exterior and twin towers that frame a large rose window, the Romanesque-Venetian architecture of this historic church make it an amazing place to see in person. We were exploring Detroit in January, so in just stepping in out of the cold, St. Mary's was a pleasant surprise to discover.