Imagine you’re walking along, minding your own business, maybe looking around a bit at the scenery, when you notice a swimming pool— and something is not right with that pool. You look a little closer, and suddenly you feel panic begin to rise, because not only are there people in that pool, they look like they’re trapped, and there’s not a lifeguard in sight. Just before you call for help, you start to really take it all in, and then you realize: this pool is no ordinary swimming hole. It’s ART, and it’s the kind that requires you to play.

The piece is called, simply and appropriately enough, “Swimming Pool,” by Argentinian artist Leandro Erlich. It’s featured in Kanazawa, Japan’s 21st Century Museum of Art, but this swimming pool isn’t the type of art you just see. For this exhibit to work, people are required to interact with it. No, not by diving in – though it is tempting! – but by simply strolling, calmly and dryly, into the pool.

So how does it work? An empty room is painted aquamarine. Its ceiling? Plexiglass, atop of which sit only about 10 centimeters (or about 4 to 5 inches) of water. That’s it, but it’s enough to create an incredible illusion. To somebody walking by the “pool,” it looks like a regular swimming arena, deep and filled with strangely-dry people. To those who venture into the aquamarine chamber – accessed via an ordinary door – it looks like they’re looking up at the world through layers of deep water. The affect is so straight-forward, but totally mesmerizing.

The 21st Century Museum of Art explains the idea behind this artistic illusion:

In one of the museum’s courtyards is a swimming pool framed by a limestone deck. When viewed from the deck, the pool appears to be filled with deep, shimmering water. In fact, however, a layer of water only some 10cm deep is suspended over transparent glass. Below the glass is an empty space with aquamarine walls that viewers can enter. The work sets up an unfolding sequence of experiences, from our astonishment at peering down and finding people under the water to our gazing upward from the interior of the pool. While undermining our everyday assumptions about what we think to be obvious, the work invites our active involvement in its spaces—once we catch on to its deception—and produces a sense of connection between people looking at each other.

It’s the kind of illusion artist Leandro Erlich – known for other incredible works like the gravity-defying, jungle-gym-esque house in Bâtiment and the melting Maison Fond – does best. In fact, before it took up residency at the museum, Erlich had even made a more low-scale version of his own. As he tells Art iT:

The first time I made the swimming pool, I built everything myself: I bent and painted the wood, I welded the metal structure, I rented a truck to pick up the Plexiglas, I applied the silicone, I put in the water. And of course that version of the swimming pool is a far cry from the one in Kanazawa, because it was really handmade. In order to make the water move on top, I installed fans that would blow across the pool, but then after two or three hours the fans would blow all the dust onto the water and I would have to get a cloth and clean the Plexiglas.

So creative, so interesting, so fun! How would you react if you stumbled upon this “Swimming Pool” without warning? Are you thinking of planning a trip to Japan to experience yourself? What other mind-bending works of art have you seen and loved? Check out more of this “Swimming Pool” in the video below from Did You Know? and tell us what you think!