The region's first castle, Castle Rest, was built in 1888; it was destroyed in the mid-20th century.[19] The most famous extant examples are "The Towers" on Dark Island, now called Singer Castle, and the previously long-neglected Boldt Castle on Heart Island, which had been left unfinished for over 75 years upon the untimely death of George Boldt's wife. It has since been completed over the recent decades in accord with Boldt's original plans.