Rare is the harried commuter who takes the time to look up when rushing to make the 6:03 to Westport in New York City’s Grand Central Terminal. They’re missing out. Originally painted in 1912 by French artist Paul Helleu, the expansive celestial ceiling mural depicts the constellations across a beautiful blue background. But, there’s a catch. Or a typically New York backstory. Shortly after the grand reveal, a commuter called out a glaring mistake…the design was backwards.

Rumor has it that Helleu painted from a rendering placed at his feet, resulting in a mirror image. While the artist was reportedly unphased by the debacle, railroad officials defended the mural, saying it was painted from God’s perspective, looking down through the night sky. When the ceiling was restored in 1944, the orientation of the mural was left unchanged.

In 1996, the terminal underwent a $200 million renovation to repair half a century’s worth of damages. At that point, the beauty of the mural had become all but forgotten thanks to a thick layer of black tar and nicotine. It took two years to restore the terminal to what we know it as today, but as a reminder of Grand Central’s once starless concourse, a small patch of black remains in the northwest corner.