English: Photograph of the largest and oldest American Sycamore Platanus occidentalis tree on the grounds of the Winterthur Country Estate Museum. According to a promotional magazine published by Winterthur, this tree may be over 250 years old. A core sample is unobtainable because around 1955, the tree had substantial core rot, and a tree surgeon devised a plan to fill the empty core with concrete, rubble, reinforced with metal bars, and even a long cable (to support a weak branch). The tree's bark and outer layers of cortex have grown back around that artificial core, and the tree survives to date (2008) because of (or despite) these efforts.