If you can't bring the people into the gallery, bring the gallery out to the people.

That's the intent behind the fourth annual Sculpture Grande, an outdoor art exhibit on until the end of October that's transformed Prague's busiest thoroughfare — Wenceslas Square — into one giant street-level gallery.

It's hard to walk down that strip these days without being confronted by one of the 23 sculptures, from small to massive, that are on display along the length of the square and down Na Příkopě.

The artwork, which took a full week to install, runs the gamut from hefty stone and metal structures that are conspicuously out of place to smaller pieces that blend into the scenery. Day and night, tourists and curious passers-by mill around or even sit on some of the works, pose for pictures and consult their maps.

The contribution of this year's star headliner, world-renowned American conceptual artist Dennis Oppenheim, sits in two places on the square: at its intersection with Vodičkova street and at the north end where it meets Na Příkopě.

In his five-piece "Aerial Water Closets," pastel-colored toilets, sinks and bathtubs appear to sway in the wind, each supported by a curvy metal stem sprouting forth from a shared base. Looking something like a sci-fi hydra creature born in a junkyard, the piece garners a steady crowd of curious onlookers and camera-snapping tourists.

"I was thinking of a hurricane interrupting the architectural dynamics of a house, the chaotic qualities of residential plumbing," said Oppenheim at the show's opening July 19. "Pipes going everywhere, nowhere ... [architecture] gone amok.

"It's also about an alternative to trees. Why must we have nature always dictate trees?"

Exhibiting in an outdoor venue, especially one as busy as Wenceslas Square, is not always an easy thing for an artist, he says.

His work is "out in the open," he says. "It's a target for everyone. It doesn't have the protection of a gallery or museum."

This vulnerability was clearly not lost on show organizers. A sign at the base of some pieces warns, "These works are being monitored by security cameras. Do not attempt to damage the sculptures."

But the risk is worth it, Oppenheim says. "The payoff is the visibility. In one day, it can get more visitors than a piece in a museum gets in a year."

Prague, too, has a special draw for an international artist like himself.