Sam Merrill is a great switchback, moderate hike and easy to find, pretty much up and back with beautiful views at top at the hotel ruins (lots of history there with signs). This is a great trail for the solo hiker, it stays pretty busy especially on the weekends, can't get lost and people to ask questions. Take Lake Ave out of Pasadena until it turns left and park anywhere, the trail head is on the right side right at the turn.