Wilshire Boulevard runs from downtown all the way to UCLA. Parts of it are quite interesting and runnable, featuring some important L.A. landmarks. Some sections are very busy and not that pleasant. This run is accessible from downtown. Start at lovely MacArthur Park, a small urban oasis with some trails and a great view of the L.A. skyline. Following Wilshire Blvd. west, you’ll pass some cool landmarks, including numerous embassies & consulates, interesting temples, hip hotels and restaurants, and theaters & concert venues. Near the 5-mile mark is the La Brea Tar Pits, an ice Age–fossil excavation site with an adjacent museum, plus a re-created prehistoric garden, and the L.A. County Museum. There are some nice walking trails around there. The L.A. metro runs right along Wilshire Blvd. from downtown, so one option is to run one-way and hop on the metro back. For variety you can go out Wilshire and return along 6th St.