20 Francs Belgium

The Belgian 20 Francs coin, struck from 1966 to 1980, featured a portrait of King Baudouin that remained unchanged for 15 years, a rarity in an era of frequent redesigns driven by politics and inflation.

This nickel piece was minted at the Brussels facility, weighing about 10 grams and measuring 29 millimeters across. It replaced earlier silver versions, reflecting Belgium's pivot to cheaper metals as global silver prices soared. The obverse showed the king's profile, while the reverse depicted the Belgian coat of arms with its distinctive lion. Not every year saw production; some, like 1972, might have been skipped, though records are spotty.

Collectors sometimes overlook these coins because they're common in circulated grades. If you find one in proof condition, it's probably stashed in a drawer somewhere, not a vault.