McMurdo is on Ross Island on the coast of Antarctica. It is locked in by sea ice for most of the year. About 1000 people (scientists and support staff) live there in the summer (Nov-Feb). It's the main base for getting to lots of other places in Antarctica...like the South Pole. Here's a good short link about McMurdo McMurdo.
Click on any picture to enlarge

C-17 pallets passengers
View from C-17 - Mountains in Antarctica View from C-17 - sea ice Unloading
McMurdo McMurdo McMurdo