The Stella Australis cruise was breathtaking. I boarded from Ushuaia, saw Cape Horn, Eagle Glacier and Magdalena Island (which I refer to as Penguin island) before arriving in Punta Arenas.
By far my favorite part was seeing the hundreds (maybe thousands!) of penguins on Magdalena Island. They don't have fear of people, so we were advised to yield to them as groups of penguins pass along the walking trail.
I had never seen a glacier before, so that was another highlight of the trip. The brilliant blue and turquoise color that radiates from the crevices of the glaciers is pretty remarkable. You can't catch it completely on camera.