The West Trail is closed until further notice due to damage caused by the Sunset Fire, but the rest of Runyon Canyon remains open.
This 160-acre park at the eastern end of the Santa Monica Mountains has one main loop, plus a bevy of dirt hiking trails. It's also got one of the friendliest off-leash dog policies. The sea of buff trainers and their sleek, sweaty clients can get to be too much during the busy morning and weekend workout traffic, but you'll be rewarded with some of the best views of the city (and, if you're lucky, a chance to gawk at power-walking celebs).
The southern entrance is at the end of Fuller Avenue in Hollywood; the northern entrance is off the 7300 block of Mulholland Drive.