From Ushuaia, “mas austral del mundo” — the southernmost city in the world. It was written just before the trip to Antarctica. Of course the man himself will be back in Australia the day after tomorrow.
As an Australian, I did a double-take at one of the pictures on the postcard:
Hands Cave and Pinturas River Canyon…an amazing display of cave art 9,300 years old in the heart of southern Patagonia
See: another entry called Postcard from Patagonia, this one on New Matilda, by Sharon Coutts; About Argentina / Indigenous Population; The Fuegian and Patagonian People (Chile and Argentina).
And of course Charles Darwin, The Voyage of The Beagle (Chapter 11).