This 15-mile round-trip hike will take you the the top of Mount Wilson, where you'll enjoy sweeping views beside the Mount Wilson Observatory. The Mount Wilson Trailhead sits near a small park just north of Sierra Madre, and it is easily to miss if you aren't there on the weekend when you are likely to see plenty of other cars and hikers. The trail goes uphill gradually, but it feels like it almost never ends. The first part is a wide fire road that winds around the hills until you reach Orchard Camp, where the trail changes to singletrack until you reach the Bench. From here, keep an eye for a small trail next to the fire road that will take you to the top if you'd like to avoid walking on the fire road.
In 1864, a man named Ben Wilson built the trail to transport timber down from the mountain to build San Gabriel Mission. In 1889, after the timber operation was nearing it's end, the mountain became a location that was favored for astronomical observation. Harvard shipped a telescope, and two larger 60-inch and 100-inch telescopes were then installed at the top of the mountain.
The Mount Wilson Trail is the longest and most strenous way to get to the top, so it doesn't see too much traffic. This makes it perfect if you are looking for solitude. There is no water source in this trail, so make sure you bring enough water during the summer; the temprature can get pretty hot here.
It is a little bit jarring to reach the top and be greeted by cars and people who drive up after such a strenuous hike. Make sure to save some energy to walk around the area; there is a cafe that is open during the summer, and there are benches where you can sit and enjoy the view. The observatory is also pretty neat to see. Once you're done, you can enjoy the downhill on your return.