PARIS—A sperm whale appears to have beached on an embankment in the shadow of Notre Dame Cathedral in Paris.

Or maybe not.

A Belgian artists’ collective installed a very real-looking, life-size whale sculpture Friday alongside the Seine River, eliciting surprise and concern from tourists and Parisians alike.

Bart Van Peel, a member of the collective, said the installation is about raising environmental awareness and awakening “the child in everyone who still is puzzled about what is real and what is not.”

Kim Landman from New York was among those taken aback, especially after Van Peel spun a tale describing how the whale got stuck under a city bridge.

Parisian Charles Jean was immediately skeptical, asking whether the whale had climbed onto the quay with a ladder.