In case you have no idea what abseiling is all about, it's the art of lowering yourself safely down a rope. You wear a climbing harness, and are clipped onto the rope with some manner of descending device. You then walk backwards down the cliff face or dam wall, or whatever) supported by the rope, slowly lowering yourself down, enjoying the scenery en route.
Most commercial abseils are belayed. If you were to just let go in panic, the trip leader could safely lower you down remotely, either from above or below. It's also quite likely that there'll be a decent section of overhang, so you get to spend some time just hanging out, admiring the view.
For something a tad more extreme - rapp jumping is abseiling with the climbing ropes attached at your back instead of your tummy, so you go down face first - usually running. Not for the faint of heart.
The rock face that we used to abseil is situated on the banks of the Blyde Dam right next to the dam wall, boasting some spectacular scenery of the canyon, dam,the Three Rondawels and maybe a Hippo or two. From where you will be abseiling you will be seeing the Blyde dam wall and the overflow of the dam into the Blyde river.
Please note, no-one uder the age of 12 may participate in this activity.