Apparently the sheet of ice that sits above the south pole moves every year so the markers stay up for a few years before they are stored away.
The ceremonial South Pole is surrounded by the flags of the Antarctic Treaty Nations. You can see the dome of the Amundsen-Scott South Pole Station in the background.
Data from a GPS is used to mark the exact placement of 90 degrees south latitude. Each marker is about 12 feet long, but about two-thirds of it gets pounded into the ground. The markers are only left up for a few years before they are stored away in the South Pole Station.
http://attractions.uptake.com/blog/south-pole-markers-2317.html
From the Upcoming ueue, submitted by boodaa.
Nonetheless, when it is my turn to choose a marker, I'll erect a large bronze palm tree.
http://www.stuff.co.nz/4840139a11.html