A family-friendly campground is tucked away in South Whidbey State Park near Freeland, with two short trails leading from the campsite area. The Hobbit Trail is about .4 mile round trip. Interpretive markers lead the way, but the box is empty of trail guides. There are some fun trees to admire and a nice vantage from which to watch shipping traffic and gaze at the Olympics.
Also nearby, the more popular Beach Trail. There are three different entrances to this trail, so pay attention when you merge. The trail descends the cliff (fairly gently) to a steep set of stairs to the beach. You can hike along the beach in both directions for a nice stretch. A landslide to the south is interesting to poke around in, as the upturned trees exposed clay soil that when mixed with water is just like molding clay you buy in a store, or even a mask treatment that you'd get in a spa.
There is also a see-saw tree, and various sea creatures to find during low tide, plus the good views.