Gaze up at the magnificent celestial ceiling of the Main Concourse, and you will see 2,500 stars leafed in gold. This cerulean blue mural, envisioned by French artist Paul Cesar Helleu, showcases the zodiac constellations visible in the night sky from October to March. However, if you look closely, you might notice something strange: the constellations are painted backward. While some claim this was a simple mistake made by a researcher holding a map at his feet, the Vanderbilt family, who funded the terminal, famously insisted it was intentional—representing the sky as seen from the perspective of God looking down from heaven. If you look toward the constellation Pisces, try to spot a tiny, dark hole; that was caused in 1957 when a Redstone missile was displayed here as a show of American strength during the Space Race. For a practical tip, look for a small, dark patch in the corner near the Cancer constellation—it was left uncleaned during the 1990s restoration to show exactly how much tobacco smoke and soot had coated this ceiling over the decades.