If you've ever been to Paris's Charles de Gaulle airport, in my opinion the oddest part is the escalator type things.
Basically it is an atrium, and a few floors up where your escalator is an entirely enclosed tube crossing the atrium. There's 5-10 of these tubes.
They're not exactly normal escalators inside.
You ride a soft foam conveyor belt that is just slightly disconcerting - and to wit, my last time on these, an overweight woman directly in front of me lost her balance and fell down into me, leading to an almost cartoon-like situation where I was holding on with each arm to the railing on each side trying to stop a cascading effect, because if I fell then we were probably going to take a few other people out below us.