Austin is like heaven on Earth for trail running enthusiasts (and for open water swimming). With more than about 20,000 acres of parks in the city alone, you are certain to find routes that suit your level. The 7-5 miles Barton Creek Greenbelt, which starts at the famous Zilker Park, goes though the city. When you’re done, you can go to the Hill Country and choose between dozens of single tracks. Then head to the Colorado River to run under giant cypress and pecan trees for miles. The Walnut Creek Metropolitan Park and Bull Creek are also popular locations.