Herbert George Ponting, A Cavern in an Iceberg; Scott’s Last Expedition, The British Antarctic Expedition, 1910
“Herbert Ponting was the official photographer for Captain Scott’s tragic final expedition, enduring sub-zero temperatures to document this uncharted environment. In The Great White South (1921), he recalled discovering this cavern: ‘A fringe of long icicles hung at the entrance of the grotto and passing under these I was in the most wonderful place imaginable. From the outside, the interior appeared quite white and colourless, but, once inside, it was a lovely symphony of blue and green.”
The Victoria and Albert Museum
Images found here and here. Thanks to AJWShaughnessy