Visiting purely as a stop-over between Barcelona and Paris in 2016, Lyon was a city full of surprises. We stayed in the Old Town, high above the cobblestone streets in a rustic farm house with a view overlooking the entire city. It was here we discovered traboules - ancient passageways which were once used by trade merchants to move goods and (so the story goes) hide downed Allied fighter pilots during World War II. Hidden behind doorways throughout the Old Town, most of these traboules would only reveal themselves with effort and patience, so my kids and I spent hours like we were on a treasure hunt criss-crossing the town looking for new dark alleys and stairwells to explore.