Gravois Avenue cuts a mighty diagonal through south St. Louis' 90-degree grid, and thus provides unparalleled variety for urban biking. Plus, there's plenty of room for cyclists, even during rush hour. If you start at the county line (near the River Des Peres) and head toward I-55 (where Gravois morphs into Tucker Boulevard), you get a gradual uphill pedal that can be made casual or extreme, depending on what type of cyclist you are. The scenery is ever-changing: stalwart independent businesses and ever-multiplying Bosnian storefronts; slightly suburban and ultra-urban landscapes; gently decaying and freshly rehabbed buildings; churches and fast food and funky intersections that beg you to get deliciously lost. There are obvious markers on the journey: South Side Cyclery, the Bevo Mill, the deco South Side National Bank tower, Hodak's Restaurant and the imposing spires of St. Francis DeSales church. There are hidden delights: a head shop, a miniature museum, the "Potato Chip Factory" sign, Piggy's Auto Sales and Mary's Fine Foods. There's plenty of places to eat, drink and use the bathroom along the route, which is only 6.5 miles one-way but feels like a grand adventure.