What is the only continent through which all lines of longitude pass?

Antarctica is the only continent through which all lines of longitude pass.

Every meridian of longitude converges at the geographic South Pole, which lies on Antarctica. Because lines of longitude run from pole to pole, the continent extends across every line of longitude even though most of its land is covered by the Antarctic ice sheet. This is a geographic consequence of Antarctica surrounding the South Pole, not a claim that every meridian crosses exposed rock.

Antarctica is Earth’s southernmost continent and is encircled by the Southern Ocean. Its ice sheet contains the majority of the planet’s freshwater ice and has an average thickness of roughly 2 kilometres in many descriptions. The continent has no permanent native human population, though research stations operate there year-round or seasonally.

Antarctica is also different from the Arctic. The Arctic is primarily an ocean surrounded by land, while Antarctica is a landmass surrounded by ocean. The Antarctic Treaty, signed in 1959, reserves the continent for peaceful purposes and scientific cooperation.