The Seventh Street Improvement Arches are a double-arched masonry highway bridge that formerly spanned the St. Paul and Duluth Railroad tracks in St. Paul, Minnesota. The Seventh Street Improvement Arches are historically significant for its rarity and the technically demanding nature of its skewed, helicoidal spiral, stone-arch design. The bridge is one of the few of its type in the United States, and is the only known bridge of its type in Minnesota. It was built in 1883-1884 by Michael O’Brien and McArthur Brothers of Chicago and was designed by William A. Truesdell.