A 17-meter sperm whale washed up on the banks of the River Seine on July 21, not far from the Notre Dame Cathedral. Parisians and tourists gawked from behind police tape, as forensic scientists looked over the animal. It was quite a sight in the bustling French city, and all of it was completely fake.

An exhibition by Belgian artists Captain Cooper Collective, the faux whale is meant to raise awareness about humans’ impact on the environment, especially on whales’ habitats. The collective put the hyper-real whale in a public space so that people could get up close to an animal they normally wouldn’t see. And those scientists? Just performers.

Captain Cooper has staged life-size whale beachings before, in London; Valencia, Spain; Antwerp, Belgium; and Duisburg, Germany. But even locals were fooled. Watch our video to see how some passersby reacted.