For me, one of the highlights of that trip was the chance to see, in person, the famed Arenberg Trench. This stretch of cobbles has earned an almost mythical reputation as the key sorting-out point of the Paris-Roubaix classic. It is here, usually in the rain and mud of a northern French April, that the race comes alive. While the winner is seldom decided in the Arenberg Trench, most of the losers definitely are.
But, as well as the roughness, the surprising thing for me was the gradient. I had always assumed that the "Trench" part of the name came from the fact that the road cuts through the forest, giving the feeling of riding along a trench. In fact, the name comes from the road having the profile of a trench, dropping from either end to a low point almost exactly half way along. Riders thunder downhill into the trench but the difficulty comes in the second half where they have to try to maintain their momentum for the climb back out.
We didn't get to ride it in 2010, but we did walk the full length. My sore hips were bad enough after that. I can't imaging what I'd be like after racing through.
I took some video on my phone which hopefully will give you some idea of just how rough the stones are on this iconic stretch of cycling history.