I have to show you this picture I got of the Rockland Tunnel a couple of weeks ago. This picture would never be attainable in the summer time because the sun is too high in the sky. This is one of two tunnels on our local rail trail system. The Rockland Tunnel is 5/8 of a mile long and has a very sharp hook in the end. There is a distance of about 50 feet where neither end is visible and you are in total darkness. The other tunnel is the Kennerdell tunnel. It is 3/4 of a mile in length and has a very gradual curve. You are in complete darkness for much of it's distance. Both tunnels have paved bike paths through them, so bring your bike and a good flashlight to Venango County, PA and take the ride !! It's well worth it.