Land of Ice

The Northern Continent is where all of the world's worst criminals were sent. It is presumably near the North Pole, as 500 years ago, Oars was frozen there to death, due to him wearing nothing but a loincloth. His frostbitten corpse was found by Gecko Moria.

Trivia

 * It was said that this is where the world's worst criminals were sent, which contradicts with the purpose of Impel Down.