I'm not a fan of air travel, and I'm not certainly not fond of United's "Terminal for Tomorrow" (a.k.a. Terminal One) at ORD: it's constructed largely of glass and metal, and as a result it's often unpleasantly warm.
However, I love the underground tunnel that connects the terminal's two concourses. It's home to "The Sky's the Limit," a light and sound installation by Michael Hayden. It's both kinetic and soothing, and it makes all of the hassle and discomfort of air travel fade away, at least for a few minutes.
I had no need to pass through this tunnel on Sunday--my incoming and outgoing flights were both assigned to Concourse C--but I had a long layover and needed a break. After a couple of passes through the tunnel, my spirits were indeed lifted.