My idea of a "hard climbfest" is what others would likely call the hill to get off their driveway.
A friend and I were on a ride in Atlanta just checking things out. Hit a hill over by West End/the cemetery that caught both of us quite by surprise. We tried like heck to get up it and thought it ended at a curve...we walked from the curve up...
Another time we were on a big group ride. One of the group leaders is a racer/rider on the side and just for "fun" he opted to lead the ride over the hilliest route he knew to break the group up some. A great bunch of us got dropped, so we just created our own ride as we found MARTA and other of our own ways home.