Might as well be Chinese. Or Greek. Or Heavenly Script.

The above graph, found on the Strange Maps blog, shows inter-language relations of "mutual incomprehension." For example, in English, when you encounter something that's completely indecipherable, you might say that it's "Greek to you." Then what would you say in the same situation if you were Greek? The answer is: Chinese. Chinese seems to be unique on two counts. First, it's by far the most common designate of ultimate incomprehensibility. Second, it's the only language on the list which points to a language that doesn't actually exist. Which makes sense, if you think about it. If the Chinese are aware that their language is the standard of unintelligibility for most of the world, it's only natural that they'd have to venture into the realms out of this world to find something that's incomprehensible to them.