In reply to Eeyore:
Is Tristan Dah Cunha really more accessible than the Antarctic continent? I dion't think so!!
Tristan is the most remote populated island in the world.
I think you can get flights to and from various antarctic bases from the South American continent and there are numerous cruise ships and research vessels in the south, along with around 65 manned research stations with a total population in summer of around 4000. There are numerous supply and support vessels regularily visiting these bases. You can also take any one of the numerous cruise ships and step ashore in various places along the antarctic coastline. There are numerous landing strips and safe harbours which can take ships.
Although times have moved on since I visited Tristan Dah Cunha around 1969 there is still no airport and there's only one ship visit from south africa one every two or three months (
http://www.tristandc.com/shipping.php ) The entire population is around 250 living in one small location. There is no harbour capable of taking anything other than a rowing boat or a safe anchorage. So even if you owned your own ocean going yacht you could end up visiting the place and not being able to get ashore due to ferociously rough seas.
The highest point is around 6760ft which puts in far lower than anything in our antarctic territories too.