5. Welwyn Preserve, Glen Cove, New York
Place: Glen Cove, New York, Long Island
The year is 1906.
Price: not given
The Welwyn Preserve was formerly a grand Edwardian estate, but it has long since been abandoned. Today, the abandoned grounds and greenhouses are a natural preserve that the public is welcome to explore. Welwyn was a 206-acre opulent mansion that was constructed in 1906 for oil industrialist Harold Pratt. After Pratt passed away, the estate was given to the county.

Glen Cove, New York’s Welwyn Preserve, @atlasobscura/Pinterest
However, Nassau officials let this enormous property fall into ruin since the county had no plans for it. Despite the remainder of the estate being abandoned, Holocaust survivor Boris Chartan opened the first Holocaust museum on Long Island in 1993, and it is still operating today.
