50 Dollars - Elizabeth II Pedro de Mendoza

Pedro de Mendoza founded Buenos Aires in February 1536, but the settlement lasted only four years before repeated Querandí attacks and catastrophic food shortages forced the Spanish to abandon it entirely. The city was not permanently reestablished until Juan de Garay's second founding in 1580. Cook Islands issued a wave of commemorative silver dollars in the early 1990s targeting the collector market rather than circulation, with subjects drawn heavily from Iberian exploration history ahead of the 1992 Columbus quincentenary.