The document provides information about ancient, current, and futuristic cities. It discusses Xi'an as an example of an ancient city in China, highlighting attractions like the Terracotta Army and city walls. Shanghai is presented as an example of a current city, noting its status as China's largest commercial center. Tokyo is featured as a futuristic city, citing aspects like its advanced railway system and towering skyline, including the Tokyo Skytree, that contribute to its futuristic character.