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Location: Osterville, Mass.
The Skinny: Back in January, peculiar billionaire Bill Koch—the yachtsman, collector, philanderer, businessman, and brother to conservative political activists Charles and David Koch—paid a whopping $19.5M for the Cape Cod estate owned for many years by centenarian society recluse Bunny Mellon. Koch traded up to that idyllic, 26-acre spread from this nearby compound, which he has now heaved onto the market for $15M. Though the location is enviable, on the waterfront on the ultra-expensive Osterville island known as Oyster Harbors, this pricey compound sits on just 1.58 acres. The main house, a heavily-altered nine-bedroom affair dating to 1929, is joined on the property by a swimming pool, a deep-water dock, and beach house. The interiors reflect Koch's extravagant and eccentric taste. There's even a game room outfitted to look like the interior of an old ship—Koch once sailed in the America's Cup.
· 177 Seapuit River Road [Robert Paul]
· Bill Koch Lists His Osterville Compound For $15 Million [Curbed Cape Cod]
· Bunny Mellon Unloads Epic Cape Cod Estate For $19.5M [Curbed National]