Kew Gardens 50p (2009)

For years this was the benchmark rarity of the hunt. Christopher Le Brun's design shows the pagoda at Kew encircled by a vine, marking 250 years of the Royal Botanic Gardens, and just 210,000 were struck for circulation. Change Checker named it the scarcest 50p in circulation in February 2014, and it only slipped to second when the 2023 salmon arrived. In change, look for the 2009 date: the Kew coin dated 2019 was a brilliant uncirculated reissue for the 50p's 50th anniversary and never entered general circulation.