Answer: Juneau, Alaska

If today’s trivia question gave you pause, it should. The question is as curious as the geographic oddity on which it hinges. Among all the capital cities in the United States, big and small, there is only one capital city that is completely cut off from the surrounding land: Juneau, Alaska. Even the capital city of Hawaii, Honolulu, is still linked to the rest of the main island, O’ahu, by highway.

Juneau, Alaska, however, is quite the geographic oddity as there are no roads linking it to the rest of the state. In fact, the city is only accessible by plane or boat. Why no roads? Not only is the surrounding terrain prohibitively rugged, but unlike other areas of the world where road builders press on despite rugged terrain, there is little to no economic incentive to build roads in the first place. There’s simply nowhere to go that would justify the expense.

Because Juneau is located deep in the lower panhandle of Alaska, it would require hundreds of miles of highway and huge bridges to even begin to reach into the heart of the state and connect with other significant Alaskan communities. Just to connect Juneau to the nearest existing highway would require roughly a hundred miles of highway carved through a mountain range coupled with a bridge–and even then it would require an additional meandering 756 mile journey via the existing highway system to get to the state’s largest city, Anchorage. As such, it was and has always been more effective to run Juneau as if it were an island, with all goods and materials brought in by plane or boat.