The Billy Goat Trail at Great Falls

Q: If it's called the Billy Goat Trail, how hard can it be?
A: Pretty darn hard.

Section A of the Billy Goat Trail is on Bear Island and traverses rough and rocky terrain, including a steep climb along a cliff face along the Potomac River's Mather Gorge. Hikers should take caution. At another point in the trail, hikers are required to scramble over and around huge boulders.

http://en.wikipedia.org/wiki/Billy_Goat_Trail

"A cliff face?!" Yep:

Click for a larger image.

A couple days ago, I hiked the trail with John, who's 20 years older than I am. It took us 2 hours to walk/climb/scramble the 1.7 mile course. I'm still aching but I'm afraid to ask how John's doing for fear he'll tell me he's never felt better.