Three Sisters Waterfalls, If you haven't been there yet then you should definitely make the hike. Off of Highway 79 near Descanso you can park at the 3 Sisters Waterfalls Trailhead for a hike as challenging as it is beautiful.
At a distance of about 4 miles and elevation gain of 1,000 feet you can expect the hike to take you about 3 hours roundtrip, depending on your skill level.
Equipment: You definitely want to make sure you have a good set of hiking boots for this trip, there are a lot of people attempting it in running shoes, but that's a great way to twist your ankle. Also, you're going to want to make sure you bring plenty of water. A rope and some gloves might be helpful as well and there may also be poison oak on the way so make sure you wear long pants and long sleeves.
To Get There: From Highway 79 exit (the Descanso exit) and drive north. After 1.3 miles turn left on Riverside Drive. Continue 0.6 miles to the main crossroads (post office, etc.) of the hamlet of Descanso. From there take Oak Grove Drive 1.6 miles to the intersection of Boulder Creek Road on the right. Follow Boulder Creek Road north for 13.0 miles (the first half is paved and the rest is dirt) to a hairpin turn where unpaved Cedar Creek Road joins from the west. Park there, at the 3 Sisters Waterfalls Hike Trailhead taking care not to block traffic, and post an Adventure Pass on your car. (This hairpin turn and intersection can also be reached, more circuitously by way of Engineers Road or Pine Hills Road to the north.)