This land was originally patented by Thomas Owsley in 1696 with the caveat that he had to build a house on the land within a year or forfeit rights to the land. It’s believed that Owsley built the stone house that sits at Dawson Terrace Recreation Center, one street west of the Spring Site. If true, it is the oldest house in Arlington county.

The stone house had many owners, including George Mason, to whom the land was regranted in 1767. Mason’s grandson John lost the house to the Bank of the U.S. in 1833. In 1859, the stone house and spring were purchased by Thomas Dawson, who named the house Rio Vista.

In 1861, During the American Civil War, Fort Bennett was constructed nearby by Union troops. That same year, Dawson’s daughter Bessie Lola was born. She later married William Conway Bailey and lived at Rio Vista until her death in 1955.

In 1936, part of the property known as the Spring Lot was purchased by Dr. Bay Jacobs, a prominent doctor who built a large castle on the property with his wife Eva. He instructed the stonemasons building the castle to fashion the hexagonal spring house that still stands today.