If you park at Cleveland Park (ample spaces) and run towards downtown and the gorgeous Reedy River Falls and then back it is a 5k. If you run in the other direction and get lost because the signage can be a bit confusing it's not as pleasant or fun and can be a bit longer. The trail is well traveled and maintained, and running past the shops along the riverfront is always fun for people watching, it also gives you a great downhill on the way back. Oh and as a treat the Monkeys might be making crazy noises as Cleveland Park backs up to the zoo. All in all a great experience!