Not totally sure why, but Hoppy likes to go for a walk on our 6th floor hallway early in the morning, and my wife enjoys taking him everyday. I suggested going to one of the tiny parks down the street instead, since the hallway is basically bare, with seemingly nothing to interest a rabbit except grime from nearby factories and dead cicadas. She basically told me I was crazy, noting that some websites warn of some poisonous grasses or other plants that bunnies should stay away from. So that's that.
As for Hoppy, he doesn't mind one bit. It's hard to tell from these pictures, but the little dude flies up and down the hallway... and sometimes up or down the stairs to other floors!
Heh. I guess this is one thing about the hallway that would interest a rabbit. Even animals enjoy looking at the dawn sky, huh?