1 Dollar - Elizabeth II 4th Portrait - Discover Australia - Kakadu

The Discover Australia series, launched by the Perth Mint in 2008, applied pad printing technology to bring color to proof silver issues — a process borrowed from industrial manufacturing that deposits ink onto the coin's surface without affecting the die-struck relief beneath. Kakadu National Park, the subject here, had been nominated for UNESCO World Heritage listing across two separate inscriptions: natural in 1981, then cultural in 1987, one of very few sites worldwide listed under both criteria simultaneously.