1993 Jeju Volcanic Island 500 Won

This 1993 500 Won coin from South Korea depicts the rugged basalt columns of Jeju Island's volcanic landscape, a direct nod to its UNESCO World Heritage status.

That design choice was practical; the Korean Mint used detailed engraving to capture the island's geological quirks, like the hexagonal rock formations, on a copper-nickel planchet. No gold or silver here—just a sturdy everyday metal for a commemorative piece.

We don't know the exact mintage figures, as records from that era can be spotty. What is clear is that it circulated briefly before becoming a favorite for thematic collections.

Oddly enough, its value hasn't erupted like some might expect.