Long-sustained westerly winds shaped the dunes surrounding the Saudi Arabian oasis of Jubbah in this photograph shot by an astronaut from the International Space Station (ISS). A paleolake is an area where a lake previously existed, but no longer holds any water due to a change in climate. Prior to the desertification of the Arabian Peninsula, Jubbah Lake was one of a network of freshwater sources in what was then a more humid environment. Even as the region became more arid, Jubbah Lake likely continued to hold freshwater for some time due to its position amid the groundwater-recharging dunes. This continuous, extended period of freshwater made Jubbah a destination for early humans and animals in the Nefud Desert.