The passage tells us that…………. .

The central Arctic is an ice mass formed from part of the ocean, whereas the Antarctic is continental. Surrounding the Arctic are land masses which, in most cases, extend southward to the tropics. The Antarctic, on the other hand, is the only continent entirely set off from the rest of the world by great oceans. Furthermore, at some point of man's history, all of the other continents, except Australia, were joined by land bridges. Even Australia had been easy to reach by canoe. However, the only place Antarctica even approaches another continent is the long finger of the Antarctic Peninsula, reaching within 600 miles of Cape Horn, the southernmost tip of South America. In addition to distance, ice and stormy seas kept anyone from seeing this continent until about 1820.