18. Reykjavik, Iceland The world's most northerly capital is quirky, beautiful and just a little wild. In the summer, the city is in near-perpetual daytime with about 22 hours of sunshine -- so there's plenty of time to explore. And in winter, visitors can chase down the northern lights and take in the view of a lifetime. In addition to natural wonders and outdoor adventures, Reykjavik offers a vibrant arts community, a legendary nightlife scene and geothermal waters.