Amazing graffiti art painted on the outside of a flood wall along the Mississippi River, just south of downtown (stretching from Chouteau Avenue south to Russell Blvd., a two-mile stretch). Not just your run-of-the-mill graffiti here, either, kids. This is some great stuff. The painting of this wall is actually an annual event that takes place Labor Day weekend. St. Louis, a so-called "conservative" city, has the largest graffiti art event in the world! The height of the wall varies from 15 to 50 feet. The historic MacArthur Bridge marks the beginning of the wall, as it spans out over the wall and into Chouteau's Landing, an old historic area south of downtown filled with warehouses and industry.