The C&O Canal Towpath is a bike trail that winds its way through Maryland along the old canal. It eventually ends in Georgetown, Washington DC but there are some beautiful features along the trail. My favorite spot is the Paw Paw tunnel, which is great fun to bike through! The canal is pretty full here too and you can spot turtles, wood ducks, snakes and maybe some deer along the water. Bring a light for the tunnel!