One of Barcelona’s original “milk bars,” M. Viader invented the drink you see next to the sodas in every cooler: Cacaolat. It’s exactly what you might think from the name—chocolate milk—and Catalans of a certain age gush with nostalgia over it. The founder was instrumental in getting pasteurized milk products out to the public, and this wonderfully old-fashioned cafe, founded in 1870, still serves coffee, pastries, sandwiches, exceedingly thick hot chocolate (a “suiza” is topped with whipped cream), and, of course, chocolate milk. In the morning, you can also get hot churros to go with the hot chocolate.