When other parts of the Netherlands start to feel too stereotypically quaint or touristy, head to Rotterdam, the nation's second-largest city and one of the busiest ports in the world. The riverfront downtown was virtually destroyed in World War II. What sprang up in its place is a skyline of fun and fanciful modern architecture. Rotterdam felt to us like a vibrant, culturally diverse, and decidedly unstuffy place. We were lucky enough to rent an apartment near the Blaak train station, overlooking the city's biggest street market and some of its most famous modern buildings.