The town that gave the country (and port wine) its very name, Porto is Portugal’s second-largest metropolis after Lisbon. Sometimes called Oporto, it's an age-old city that has one foot firmly in the industrial present. The old town, centered at Ribeira, was built on the hills overlooking the Douro River, and today is a UNESCO World Heritage Site. The 14th-century São Francisco church is a main attraction, as are the local port wine cellars, mostly located across the river at Vila Nova de Gaia.

If you currently think your neighbourhood coffee shop is nice, you might want to stay out of Vienna’s coffeehouses. After you’ve gotten used to these palatial, yet welcoming cafes—and their delicious coffee and Sacher torte—your local café will pale in comparison. Between coffee breaks, visitors can explore Vienna’s Schonbrunn Palace and Imperial Palace. And if you have a chance, catch a performance at the State Opera House—it’s not to be missed.