There is poetry (in Kryptonian) on certain walls
Snyder: "On the walls inside you can see classic Superman poetry, where he talks about the different moons. Then there’s this [American mythologist and writer] Joseph Campbell-ian thing that I love which I felt was really appropriate to Superman. It goes like this:
'We have only to follow the thread of the hero path, and where we had thought to find an abomination, we shall find a god; where we had thought to slay another, we shall slay ourselves; where we had thought to travel outward, we shall come to the center of our own existence. And where we had thought to be alone, we shall be with all the world.'
"Joseph Campbell says this about the hero’s journey and I always thought it was super-appropriate for Superman. That’s his whole story in a nutshell, so we put that in Kryptonian on the walls."