We have solid evidence that the Discworld rotates around a common centre (the Hub) rather than resting in place on top of the World Elephants. This means that no part of the Disc is permanently over an elephant's back.
As the pace began to quicken and the complicated threads of the chant
began to rise Rincewind found himself watching, fascinated. He had
heard about the Old Magic at University, although it was forbidden to
wizards. He knew that when the circle was spinning fast enough against
the standing magical field of the Discworld itself in its slow
turning, the resulting astral friction would build up a vast potential
difference which would earth itself by a vast discharge of the
Elemental Magical Force.
*There are, of course, two major directions on the disc: hubward and rimward. But since the disc itself revolves at the rate of once every eight hundred days (in order to distribute the weight fairly upon its supportive pachyderms, according to Reforgule of Krull) there are also two lesser directions, which are Turnwise and Widdershins.
Since the disc’s tiny orbiting sunlet maintains a fixed orbit while the majestic disc turns slowly beneath it, it will be readily deduced that a disc year consists of not four but eight seasons. The summers are those times when the sun rises or sets at the nearest point on the Rim, the winters those occasions when it rises or sets at a point around ninety degrees along the circumference.
The Colour of Magic
And then there’s momentum. Slow as the disc spins, various points of
its radii are moving at different speeds relative to the Hub, and a
wizard projecting himself any distance toward the Rim had better be
prepared to land jogging.
Lords and Ladies
The Discworld turned against the glittering backdrop of space, spinning very gently on the backs of the four giant elephants that perched on the shell of Great A’Tuin the star turtle. Continents drifted slowly past, topped by weather systems that themselves turned gently against the flow, like waltzers spinning counter to the whirl of the dance. A billion tons of geography rolled slowly through the sky.
Feet of Clay
Quite how this all works isn't clear. It's probably best not to think too hard about it.
But this is the Discworld, which has not only the turtle but also the four giant elephants on which the wide, slowly turning wheel of the world revolves.*
*People wonder how this works, since a terrestrial elephant would be unlikely to bear a revolving load for any length of time without some serious friction burns. But you may as well ask why the axle of a planet doesn’t squeak, or where love goes, or what sound yellow makes.