What was the first optical illusion ever made?

The first optical illusion is often attributed to ancient Greek philosopher and mathematician Euclid, who described various visual phenomena in his work. However, one of the earliest documented optical illusions can be traced back to the 4th century BCE with the "Penrose triangle" or "impossible triangle," which depicts a three-dimensional object that cannot exist in reality. Additionally, the "Cave of Lascaux" in France features paintings that create depth perception, showcasing early understandings of visual tricks.