Where in relation to a mid ocean ridge would you find the oldest oceanic lithosphere?

The oldest oceanic lithosphere is found at the edges of ocean basins, far away from the mid-ocean ridges. As oceanic plates move away from the mid-ocean ridge where they are created, they cool and become denser. This causes them to sink into the Earth's mantle at a process known as subduction. The oldest oceanic lithosphere is therefore found at the edges of ocean basins, where it is being subducted back into the Earth's mantle.