看不見的城市

Missing, extremely new, or very obvious to obtain.

Probably a reference to a novel of the same name, by Italian writer Italo Calvino. Invisible Cities is framed as a conversation between the Mongol emperor Kublai Khan and Marco Polo. The majority of the book is composed of brief prose poem describing 55 fictitious cities that are narrated by Polo, many of which can be read as a commentary on language, culture, time, memory, death, or human experiences.