Mammoth Cave Kentucky Key Ring. A Bright Gold Colored Metal Octagonal Charm Style Fob with Snap Bead Chain. Front of Fob shows a Raised Design Illustration of the Inside of the Cave. Back of the Fob shows an I Bring Good Luck Message with Various Symbols of Luck. Fob is about 1 1/2 Inches at Widest Points. Unknown Metal, Unknown Vintage and Unknown Origin. Used but not Abused.