The Great St. Louis Zoo is truely an amazing place to get some fun walking exercise.
The Zoo is one of the best in the nation and it's free to get in. Take advantage of this wonderful facility. Depending on your age and health, the Zoo can be a nice stroll or a safe yet challenging choice for a walk.
The rolling hills in the Zoo offer some mild incline challenge to raise your heart rate up a bit (seniors); but you have the safety of numerous Zoo staff all around you. The Zoo is a great place to get in some laps and see many beautiful animals and habitats at the same time; Try it out.
Basics: Trail: Paved Terrain: Flat with very mild hills