Mud Island is a small peninsula jutting into the Mississippi from downtown Memphis, connected to the mainland by a pedestrian bridge and monorail. The park's defining feature is the River Walk — a scale model of the entire lower Mississippi River, from Cairo, Illinois, to the Gulf of Mexico, rendered at 1:1500 scale. You can walk the length of it in about 45 minutes, with the river's curves, tributaries, and cities marked along the way, ending at a scale model of the Gulf that you can wade in during summer.
The Mississippi River Museum traces the history of the river from the first Native American inhabitants through the steamboat era, the Civil War, and the great floods of the twentieth century. It is well-done and genuinely informative, with artifacts, reconstructed scenes, and a full-size replica flatboat. The park offers striking views of the river and the Arkansas bluffs across the water. Getting there involves either the bridge from Adams Avenue (free) or the monorail (ticketed).