Sail through Neptune's Bellows into the flooded caldera of an active volcano and, if geothermal conditions permit, take an otherworldly swim in warm volcanic sands — in Antarctica. One of the most surreal and photographed moments in all of expedition travel.
What to expect
Neptune's Bellows is a narrow gap in the caldera wall barely 230 metres wide — entering it aboard a small expedition ship is cinematic in itself. Ashore at Whalers Bay, rusting whale-oil tanks and collapsed wooden structures from a 1906 Norwegian whaling operation stand half-buried in volcanic ash, creating a hauntingly beautiful industrial ruin. Walk to Pendulum Cove for the famous geothermal beach: dig your hands into the black sand and feel warmth rising from beneath. On good days, guests wade into the shallows where volcanic heat meets Antarctic seawater — a cocktail of extremes. Your volcanologist explains the island's ongoing seismic activity, making every step feel charged with geological energy.
Good to know
The swim opportunity depends entirely on current geothermal output — some seasons are warmer than others. Bring a swimsuit regardless; even a shallow wade is unforgettable. The Whalers Bay historic site has strict no-collection rules; photography is encouraged but leave everything in place. Landing is weather-dependent — Antarctic storms can close Neptune's Bellows to small craft.