The image below was produced by Lunar Reconnaissance Orbiter by assembling data from numerous images over six months. The levels of brightness and darkness indicate the percentage of time in which an area is sunlight. The red dot just below the rim of Shackleton shows the approximate location of the south pole.
As you can see, the rim of Shackleton Crater nearest the south pole is illuminated by the sun most of the time, while the nearby crater floor never gets sunlight. This data confirms what Japanese scientists found using their lunar probe, Kaguya. The south pole has the ideal combination of locations with nearly continuous bright sunlight (to provide power) and nearly continuous darkness (where explorers will likely find significant amounts of frozen water), making this is an excellent location to build that first lunar base. And from the image you can see that the Shackleton Crater rim is not the only spot near the south pole with these conditions.
Also, if you look at the close-up image of Shackleton’s rim that I posted here, you will see that there is plenty of room to land and set up residence.