Set on two mighty rivers and hemmed in by very steep hills, France’s second city is a place of broad vistas and flowing water, with homes, shops, and churches scattered across islands and climbing sharp slopes. Undeniably pretty, the history here is nonetheless gritty. Stepping onto a funicular dating back to 1891, I was spirited to the summit of La Croix-Rousse, “the hill that works,” an 800-plus-foot rise that was once the heart and soul of this city’s blue-collar community. While the area has since been gentrified, Lyon’s famous silk industry toiled here for centuries, the remaining 18th- and 19th-century workshops testifying to its importance. The big buildings with vaulted ceilings are still connected by hundreds of “traboules” (“to cross on foot,” from the Latin), passageways cutting between the main streets, forming a labyrinth, a city-within-the-city. Bisected by both the Saone and the Rhone, Lyon’s history runs all the way …