It’s like this: you’re walking through an art center you’ve visited several times, chatting idly as you pass the art work, stopping occasionally to study or share a comment on a particular piece. There’s a Grant Wood, there’s a Hopper, there’s a Mapplethorpe and an O’Keefe. It’s normal, it’s enjoyable, it’s casual and easy, and then you turn a corner and encounter…well, this:

It’s hard to describe. But try to imagine if the xenomorph from Alien and Tolkien’s arachnid nightmare Shelob the Great mated, and the resulting offspring could extrude packing tape. To come across it unexpectedly is wonderful — and I mean wonderful in the earliest definition of the term. It inspired wonder.

And then as you stand there gawking, you realize there’s a person inside it. A person. Inside it. And moving.

It’s an art installation by a collective calling itself Numen / For Use — three industrial designers (from Germany, Austria, and Croatia) who create large-scale, site-specific interactive projects. They’ve done similar tape projects in Melbourne, Paris, and Vienna. This is their first tape installation in the U.S. And it is spectacular.

In this case, Numen / For Use used about 1400 pounds of translucent polypropolene tape to create an object that’s a cross between a giant spider’s web and a cocoon. There’s a single small circular opening in the bottom of the installation through which it can be entered (with the help of a small stairway). Folks can crawl, scoot, wriggle, and worm their way through the installation. At some points, it’s large enough to stand up inside.

On its own, this installation is singularly strange and oddly delightful — but even more strange and wonderful are the reactions of the people. Nobody can look at this without becoming at least momentarily childlike. You want to touch it, to crawl up inside, to wander around beneath it — you want to play with it even as you admire its beauty.

My friend and I spent maybe an hour with it. Then we went for tea. Then came back again for another thirty minutes. And it’s still not enough. We’re going back again today.

It’ll be enchanting and astonishing folks in the I.M. Pei wing of the Des Moines Art Center for the next three months.