We went on a hike into a canyon the other day and came upon Sturtevant Falls. It was beautiful and it is a great hike. I highly recommend it. It's only about a ten minute drive from downtown Pasadena. The trail itself was a little under 4 miles roundtrip. There are longer trails as well. Click on the link below for more information.
http://www.modernhiker.com/2008/02/17/hiking-santa-anita-canyon/
http://www.modernhiker.com/2008/02/17/hiking-santa-anita-canyon/