Greenland

Greenland's pair records a country with no road between its towns. Nuuk is the capital, and the way to any other settlement is by air or sea because there is no connecting network to build on; Ilulissat sits beside a glacier that discharges tens of cubic kilometres of ice a year and moves fast enough to be measured in tens of metres a day. The entries are here for scale that has to be stated numerically to be believed.