Dominating the landscape at Centre Furnace is the ancient sycamore (Platanus occidentalis), located on the hill behind the Mansion. Probably 50 years older than the charcoal iron furnace that was built nearby, this sycamore began life sometime between 1736 and 1746. The tree was spared when the first cabin was built at Centre Furnace, providing shade to the mansion grounds for more than two centuries. On Arbor Day 1990, this exceptional specimen tree was pruned and its sweeping branches were cabled by local arborists to provide it with greater stability.
One other giant sycamore, probably nearly as old, is located at Centre Furnace in front of the Mansion. More recent trees have been added. The sycamore surrounded by a bench, to the left of the entry path, was given in memory of Historical Society member and friend. Ned Shilling. A line of ten sycamores have been planted along East College Avenue in front of the mansion, to introduce a green corridor to visitors entering State College and Penn State. These ten trees were a gift of former Historical Society Board member Elizabeth Sweetow.