What is the only continent crossed by every line of longitude?

Antarctica is the only continent crossed by every line of longitude.

All lines of longitude run from one pole to the other, so they converge at the South Pole, which lies on the Antarctic continent. For that geographic reason, every meridian crosses Antarctica, making it unique among the continents.

Antarctica surrounds the South Pole and is encircled by the Southern Ocean. It is the coldest, driest, and windiest continent, and most of its surface is covered by a massive ice sheet. The continent contains the vast majority of Earth’s fresh water stored as ice.

Antarctica has no permanent native population or sovereign national government. Scientific stations operated by different countries support research under the Antarctic Treaty System, which entered into force in 1961. Some maps can make longitude appear to meet at a point outside the visible land because of projection choices, but geographically the South Pole and all converging meridians are in Antarctica.