Complex sentence: The Meyer's mansion on the Seven Springs Estate in Westchester County, New York was built in 1919 with over 60 rooms, two servants wings, 15 bedrooms, three pools, including an indoor pool cased in white marble from Italy.
Split into simpler sentences: The Meyer's mansion on the Seven Springs Farm in Westchester County, New York was built by them in 1919. The house had over 60 rooms, two servants wings, 15 bedrooms, three pools, including an indoor pool cased in white marble from Italy.