At a depth of over two miles, liquid Lake Vostok has sat unseen for perhaps 35 million years.
A wooden sled sheathed with a metal bottom is the vehicle of choice. At the back end on the bottom, a one-use sheet of plastic is attached, and by leaning back and pulling on the rope attached to the front of the sled, you can reduce your contact point to nothing but this slick surface, achieving speeds of 50 to 60 mph!
A long time ago, Timbuktu was pretty far from anything else. It still is. Timbuktu is in Mali, Africa, and while there are scattered towns at some distance to the south, to the north is the vast emptiness of the Sahara Desert.