Do deserts have underground water?

Over many years, the plate surface of the earth has shifted and there are chances for the water sources to be present below the deserts as well. We normally may not expect this because of the dry nature of the land. We normally may think of the water sources having developed as a result of surface water seeping underground. But this does not have to be the case.

It is known that the underground water can literally travel many hundreds of kilometers from its water source. Some very dry regions like desserts can have some heavy water sources. These water supplies can be quite large and vast. But unfortunately, the land above remains as a desert, and the water is useless.