Although there's more than one definition of "the South Pole", the most popularly accepted one (and a travel destination) is a fixed location in the southern hemisphere at the Earth's axis of rotation, latitude 90°S (longitude not applicable). Unlike the North Pole, which is covered by nothing but a sheet of ice floating on the surface of the Arctic Ocean, the geographic South Pole is located on solid ground, allowing a permanent research station to be built at the site of the pole itself. Although it was once an elusive goal that took the lives of many explorers, thanks to modern technology, it has been permanently staffed since 1956, and is now a destination of commercial travel expeditions.
"The South Pole" is also defined geomagnetically. This pole drifts around, and since there's nothing particularly interesting about it other than perhaps watching your compass not work, it receives no visitors. There's also a southern pole of inaccessibility, the point in Antarctica farthest from any coastline. This is a fixed location (barring major sea level changes that might redefine coastlines) at 85°50'S 65°47'E, but as the name suggests, travel to this point is generally impractical.
It's tempting to say that the climate at the South Pole is consistently bone-chilling cold, but it is not. In December it is bone-chilling cold, with an average temperature of around -28℃ (-18℉). In July it is astonishingly bone-chilling cold, with temperatures sagging to -80℃ (-112℉). (Note that there are no "day-time highs" or "night-time lows" in these figures, because the sun only sets and rises once each year.) Snowfall is scarce; the temperature is usually too cold to create snow. The existing snow does drift heavily, however, with winds averaging a modest 12 knots. (At these temperatures, calculating wind-chill factors is fairly pointless.)
The terrain around the South Pole is consistently flat. Ice is fluid enough to settle to a flat surface if left undisturbed, and the underlying rock isn't geologically active, nor is there any rainfall to sculpt it.
Antarctica is (for obvious reasons) the least-visited continent, and the South Pole is (because it is not accessible by sea) the least-visited site in Antarctica that is nominally "open to tourism".
Most expeditions take place in November thru January, during the Antarctic summer/day. They generally launch from Punta Arenas at the southern tip of Chile, stop at Patriot Hills camp in the Ellsworth Mountains on Antarctica, and make the final leg of the trip by air as a day trip to the Pole itself. Some expeditions drop travelers well short of the Pole, leaving them to finish on the ice.
The area of interest around the Pole is quite compact, making it easy to get from one part to another on foot. Venturing farther afield should be done on skis or using base transportation.
There are few formal recreational opportunities at the South Pole.
The South Pole contains one of the planet's largest reserves of fresh water, but it's often frozen.
Although they are not in the habit of accommodating vistors, the facilities of Amundsen-Scott station can provide shelter in the event that weather prevents you from returning to your base at the end of your day visit.
All of the health and safety advisories for Antarctica in general apply to the Pole.
Although the ground at the South Pole is close to sea level, the thick ice at that location raises the station to an altitude of 9,300 feet (2,835 meters). And because the earth's rotation causes the atmosphere to thin out at the poles, the air pressure is more like at 11,000 feet. So in addition to preparing for the coldness and dryness of the air, travel to the Pole also requires acclimatization for high-altitude travel. (See the Altitude sickness article for more.) The altitude also makes the danger of UV exposure even greater than at the Antarctic coast.
Most visitors to the South Pole head north from there.