So what exactly makes a place thin? It’s easier to say what a thin place is not. A thin place is not necessarily a tranquil place, or a fun one, or even a beautiful one, though it may be all of those things too. Disney World is not a thin place. Nor is Cancún. Thin places relax us, yes, but they also transform us — or, more accurately, unmask us. In thin places, we become our more essential selves.

Thin places are often sacred ones —St. Peter’s Basilica in Vatican City, the Blue Mosque in Istanbul — but they need not be, at least not conventionally so. A park or even a city square can be a thin place. So can an airport. I love airports. I love their self-contained, hermetic quality, and the way they make me feel that I am floating, suspended between coming and going. One of my favorites is Hong Kong International, a marvel of aesthetics and efficiency. I could spend hours — days! — perched on its mezzanine deck, watching life unfold below. Kennedy Airport, on the other hand, is, for the most part, a thick place. Spread out over eight terminals, there is no center of gravity, nothing to hold on to. (Nor is there anything the least bit transcendent about a T.S.A. security line.)

A bar can be a thin place, too. A while ago, I stumbled across a very thin bar, tucked away in the Shinjuku neighborhood of Tokyo. Like many such establishments, this one was tiny — with only four seats and about as big as a large bathroom — but it inspired cathedral awe. The polished wood was dark and smooth; the row of single malts were illuminated in such a way that they glowed. Using a chisel, the bartender manifested — there is no other word for it — ice cubes that rose to the level of art. The place was so comfortable in its own skin, so at home with its own nature — its “suchness,” the Buddhists would put it — that I couldn’t help but feel the same way.

Mircea Eliade, the religious scholar, would understand what I experienced in that Tokyo bar. Writing in his classic work “The Sacred and the Profane,” he observed that “some parts of space are qualitatively different from others.” An Apache proverb takes that idea a step further: “Wisdom sits in places.”