Utqiagvik, Alaska
Although Utqiagvik is in North America, it is isolated from any other city. There is no road connecting Utqiagvik and other places in Alaska, which makes it impossible to drive into or out of the city. Therefore, the only way to get there is by plane. It is also possible to get there by boat, but only during a few months in the summer as the ocean is frozen for most of the year.