If you're looking for a challenge, consider hiking from the Palo Comado Canyon Doubletree Road Trailhead to the 2,405 foot elevation Simi Peak in Oak Park. This is about a 4 to 4 1/2 mile trek each way with a 1,200 foot elevation gain to the top that is well worth it if you have the time and the energy.
Mind you, this particular stretch of trail, the Palo Comado Fire Road, I've rarely seen more than a handful of hikers and runners on over the years. I usually see more cyclists up here than anything. Part of the challenge is that it can get pretty hot up here on these trails as most of them get full exposure to the sun. So do bring plenty of water and wear sunscreen unless it happens to be a rare, overcast day. No restrooms either.
A quicker, easier path to the panoramic Simi Peak, the highest point in the Simi Hills, is via the China Flat Trailhead.
So if you're up to the challenge, park your car near the trailhead on Doubletree Road , just east of Clear Haven Drive, in Oak Park. From the 101, take Kanan to Sunnycrest Drive, and make a right. Sunnycrest becomes Doubletree after it veers left. The trailhead is on the right.