Switchback

Steam Train on the Devil's Nose Switchback, Ecuador
Reading about the railroad over Stevens Pass in Washington, I discovered that the term switchback originally referred to a railway that used a switch to reverse direction when going up a hill. "Well, strictly speaking, railways do not consider something a switchback unless they have to "stop, switch, and back". The original railway over Stevens Pass incorporated eight or nine switchbacks.

Update December 2016 replaced dead link with one that leads to a 'local' copy.