Is there military fortifications in Antarctica?

Answer 1

As Antarctica has never been permanently settled by humans, there has historically been little military activity in the Antarctic. While the Antarctic Treaty, which came into effect on June 23, 1961, bans military activity in Antarctica, military personnel and equipment may be used for scientific research or any other peaceful purpose (such as delivering supplies) on the continent.

The Antarctic Treaty specifically prohibits military activity on land or ice shelves below 60°S. While the use of nuclear weapons is absolutely prohibited, the Treaty does not apply to naval activity within these bounds (in the Southern Ocean) so long as it takes place on the high seas.

So the answer is No :)