The Santa Ynez Waterfall Trail, which is part of Topanga State Park, is a relatively flat (300 feet in elevation gain) and easy trail that starts above the town of Pacific Palisades and leads to the waterfall in the name, a trip of about 2.25 miles round trip.
It is a good trail for kids, but watch out for the plentiful patches of poison oak lining the trail, often very close to the walking path. There is a trail junction about half a mile from the trailhead. One path leads to the waterfall, while the other heads to Trippet Ranch and the Musch Trail to Eagle Rock, a steep strenuous hike of about 3.5 miles from this point.
Thanks to California’s ongoing drought, the waterfall was fairly disappointing as of Spring 2016. There is a trickle of water bouncing down the rocks, and at the base are several small pools that contain newts.
This is an out-and-back trail so once you’ve had your fill of the falls, simply turn around and head back to the trailhead via the same route (while continuing to watch out for all that poison oak).