Spain’s third-largest city has long been neglected by tourism in favor of well-trodden Madrid and Barcelona, but sunny Valencia has been biding her time and is now coming into her own. It’s the birthplace of paella, where the authentic dish is cooked over orange-wood fires. Tree-lined streets teem with oranges (but not the same ones that are squeezed into the agua de Valencia that you’ll sip in summertime). And beaches fill with sunseekers enjoying chiringuitos, where the party stretches into the late hours. Valencian energy really comes alive, though, during Las Fallas—a festival where the whole city becomes one, 200 pounds of gunpowder unite everyone’s heartbeats, and the streets merge…