Mountainous
Which is harder? Ascending or descending a mountain?
A man who did a lot of mountain climbing said without a doubt descending, because ascending you were so focused on reaching the top, you avoided mistakes.
"The backside of a mountain is a fight against human nature," he said. "You have to care as much about yourself on the way down as you did on the way up."
p/s Taken from a very inspiring book.