Basically, the Conservancy and Washington International School were carved out of the Estate. The estate covers the historically unified buildings and gardens. Since the 1980s, the school bought the buildings and a nature conservancy organization (Tregaron Conservancy) preserved the gardens as a park (also called Tregaron Conservancy), but the school should not be marked park because the grounds are not open to the public. The two cooperate, and share some access (north road) but are distinct landowners with different land uses. I don't think it's redundant to keep the estate area, since it has historic preservation status, and is noteworthy in its own right. What do you think?