Modern Ghost Town, Ordos, China

Alexandria, the second largest city Egypt, was a flourishing city in the Ancient era, but declined during the Middle Ages. With only 150 residents in the early 19th century, it was classed as a ghost town. During the modern period, it has grown to a city 3.5 to 5 million inhabitants. In Algeria, many cities became hamlets after the end Late Antiquity. They were revived with shifts in population during and after French colonization Algeria. Oran, currently the nation's second largest city with 1 million people, was a village a few thousand people before colonization.
Foncebadon, a village in Spain that was mostly abandoned and only inhabited by a mother and son, is slowly being revived due to the ever-increasing stream pilgrims on the road to Santiago de Compostela.