The Arlington Peak Hike is one of my favorite Santa Barbara hikes in the front country. With about 3,000 feet in elevation gain, this hike is quite strenuous. And in the last portion of the hike you get to boulder through large sandstone formations. The combination of different grades of elevation gain make this hike very interesting.
To begin the hike, park near the water reservoir at the end of Tunnel Road and walk up Spyglass Ridge fire road. This area is a popular recreational area in Santa Barbara and it can be hard at times to find parking near the water reservoir. Make sure to not block the road and to park on the side well behind the line. Otherwise there is a good chance that you will get a parking ticket.
The first section of the trail is on a paved fire road. At the first junction, after the paved road, make sure to stay on the left of the trail. After about 0.75 miles you will see a creek crossing. Until this junction, the Inspiration Point Hike (or Jesusita Trail) and the Cathedral Peak Hike are identical. But in order to continue on the Cathedral Peak Hike, you have to go up the creek bed for about 100 yards and the trail continues on the left. This part of the trail is not very well maintained and the junction can be hard to find at times.
You will stay near the creek for a little while. After another mile or so you will hit the first sandstone rock formations. The trail is very primitive at this point and it can be very hard to find the right route up. But do not give up, the views from the top of the peak are breathtaking and make the bouldering through the sandstones totally worth it.