Over the weekend we dropped by The Onderdonk House in Ridgewood, Queens (stop by yourself for their annual Harvest Festival on October 10th!). The home, which was built in 1709, houses a large rock in its back yard (surrounded by a tiny white picket fence) known as the Arbitration Rock. So what is this thing? This single object ended a century-old boundary dispute between Brooklyn and Queens. From their website:

"The most prominent marker along the January 7, 1769 Survey Line, settled the century-old boundary dispute between the towns of Bushwick and Newtown, and the counties of Queens and Kings. The rock was originally located 297 feet northwest of the Vander Ende-Onderdonk House, several feet below the current roadbed of Onderdonk Avenue. It was buried about 1930 when the area on the northerly side of Flushing Avenue was graded in preparation for the opening of part of Onderdonk Avenue. Arbitration Rock was moved to its current site behind the Onderdonk House along the old boundary line on August 8, 2001."

Unsurprisingly there have been arguments over which borough gets to keep the rock—and shockingly Marty Markowitz hasn't gone over there to split it in half yet. Not everyone agrees that this rock is even the original boundary marker, however. According to Forgotten-NY, the Greater Astoria Historical Society's Bob Singleton says it's really "a large rock at Varick Avenue and Randolph Street, a couple of blocks away in Brooklyn, [that] should be the focus of the public's attention. 'If authentic, it's nearly 100 years older than Arbitration Rock, and designates the original 17th century border between Brooklyn and Queens.'"