25 Dollars - Elizabeth II Expo'70 Osaka

Expo '70, held in Osaka from March to September 1970, was the first World's Fair hosted in Asia and drew over 64 million visitors — a record that stood for decades. The theme, "Progress and Harmony for Mankind," reflected Japan's postwar economic ascent at a moment when the country had just posted the second-largest GDP in the capitalist world. Cook Islands has issued commemoratives under its own authority since 1972, despite using New Zealand currency domestically, making these collector-market pieces a function of licensing agreements rather than any domestic monetary need.