On a windswept Baltic island in 2022, locals gathered at a medieval castle to honor Louis Kahn – a native of Saaremaa, Estonia, who became one of the twentieth century’s most influential architects. It was at Kuressaare Castle, looming large in Kahn’s early childhood, that his imagination was sparked; fittingly, the final design of his life stands on another island half a world away, at New York’s Roosevelt Island.