This is a cover I got back recently from the Ukrainian Antarctic research station Vernadsky. It's hard to make out but the name of the base and it's co-ordinates (65° 15 S, 64° 15 W) are shown on the top half of the postmark. I believe I sent it to the Ukrainian "National Antarctic Research Center" (Національний антарктичний науковий центр which is shown on the postmark) for forwarding to the base in September of 2011. That would explain why two of the stamps are from that year. A picture of the base appears on one of the 2009 "Preserve the Polar Regions" stamps.
Vernadsky Station is located on Galindez Island on the Antarctic Peninsular south of US Palmer Station. It's a permanent year-round base with a staff of 12. It was once a British base known as Faraday station that was sold to the Ukraine in 1996. Apparently it's popular with tourists and home to the southern most public bar in the world.