this is one of the best hiking trails the I ever done, really challenges you.

This is a pretty challenging loop, but it covers two absolutely wonderful canyons. You pass the ruins of the observatory first, then the views get better as you get higher. The upper part of middle Sam Merrill trail is in a heavily forested canyon, very quiet and lush. Castle canyon on the way back is steeper, so a little better for the downhill leg. Note the freshly restored monument to Sam.

great workout loved the incline, on a clear day you get a beautiful view of LA went at sunset and was not disappointed. I went for a night hike, and wasn't the only one on the trail, a few brave runners and hikers. make sure to take headlamps and flashlights (if going for evening hike) watch your steps as well lots of support beams/ spikes sticking out of the ground

Via Crystal Castle trail its def a booty kicker! be ready for an extreme hike up..ull feel the burn. When u get to the top tho its very rewarding..keep pushing! :)

Its a moderate hike..def a good workout..the view up on top at Echo Mountain is worth it and lots of ruins left behind from back in the day. Lots of history. Check it out