庐山真面目 [- shān zhēn miàn mù](比喻事物真相) The true face of Mt. Lu — the real appearance of a person or thing; one's true character [identity]; one's true features; the truth about a person or a matter; What Lushan Mountain really looks like:
•¶ 不识庐山真面目， 只缘身在此山中。 The true face of Lushan is lost to my sight, for it is right in this mountain that I reside.