500 Francs Stamp Inverted Jennyny - The World’s Most Valuable Stamp

The first airmail stamp in U.S. history and remains one of the most expensive and legendary printing errors ever — the airplane was mistakenly printed upside down.

Today, this philatelic rarity continues to inspire collectors around the globe.

Now reimagined as a silver coin, it captivates with its craftsmanship and symbolism — a tribute not only to a unique stamp but also to an era when the dream of flight was just beginning to take shape.