The first deception happened as I sailed down the blustery Bransfield Strait and saw an icy outcrop rising out of the steely-blue waters. Deception Island initially had fooled me into thinking it was just like all the other South Shetland Islands off the northern coast of the Antarctic Peninsula. Then, like some foggy austral mirage, a small 500m-wide slit appeared in the cliffs of its south-eastern corner, and my ship, the Magellan Explorer, slipped through. The vessel squeezed into a rocky gap known as Neptune’s Bellows and emerged in the peaceful waters of an interior horseshoe-shaped harbour.

That harbour, known as Port Foster, proved to be the next deception – for it wasn’t actually a harbour at all. At least, not really. Deception Island is an alias for an active volcano, one of just two in Antarctica, and Port Foster is its flooded caldera, formed by a violent eruption some 10,000 years ago. True to its name, which was earned for these very reasons, nothing on Deception Island is quite what it seems… (continue reading at the BBC)