North on the 15, you can visit Santiago Peak (5687'). There are lots of towers on it, but the hike in, and up is good.
DRIVING ROUTE 1
From the intersection of SR 55 (Costa Mesa Freeway) and Katella Avenue in the City of Orange, go east on Katella and then southeast on Santiago Canyon Road (S18) to Silverado Canyon Road. When you meet the T intersection created by the 241, jog right, then left past Silverado Canyon Road. Keep straight.
Continue southeast another 4.9 miles to Live Oak Canyon Road (S19) with a sign "O'Neil Park". Turn left (east).
Drive 4.4 miles (just past Rose Canyon Road) to where you cross a large wash. Turn left on a dirt road in this wash. This is Trabuco Canyon Road.
Drive east 4.6 miles to a wide parking area with a road forking off uphill to the left (north). Park here.
HIKING ROUTE 1
From the parking area (BM 1746), hike north up the left-road fork, which passes a number of houses and ends at a gate in 0.5 mile.
Continue on the Holy Jim Trail to where the trail meets a road at Bear Springs (BM 3965). Turn right to the spring and hike up the trail that begins behind the spring to where it meets the road close to the summit.
Turn right on the road then switchback left and follow the road to the summit.
Another option is further north - San Gorgonio (11,499).
This is a 14 mile hike with great views. Can be done as a day hike (long day). I stayed at a designated camp group at 8,500 and made it a two day trip. You need a wilderness pass.
These is a good description here of another route,
click here.
Good Luck,
