Why Go: The snowy city island of Trømso offers unparalleled views of the northern lights (look for them between 6 p.m. and midnight) and a chance to say you’ve been to the North Pole—well, the Arctic Circle, anyway—for Christmas. Plus, there’s dogsledding, great food, and a mountaintop cable car. Here, “day” is just a couple hours of twilight blue. Where to Stay: Most hotels shut down for the holiday, but not the Clarion Hotel Bryggen, right on the harbor. The views of Trømso Sound are best ...