Ireland 24.3.1976 P-67c PMG Gem UNC 66 EPQ 20 Pounds
From the popular "Lady Lavery" series of Ireland, which was first printed in 1928 and remained in circulation until the 1970s. The three highest denominations, including the 20 Pounds, are large-size banknote that highlight the unique design, making them a collector's favorite. However, thanks to the large size, finding Gem Uncirculated examples as seen here is difficult.
PMG Population in 66 EPQ: 16 (3 Finer)