Kate Macy Ladd built Natirar between 1905 and 1912. Heiress to a Massachusetts fortune rooted in whaling, shipping, and oil, she and her husband Walter Graeme Ladd created an estate that reflected the scale of turn-of-the-century wealth in the New York exurbs. The main residence sat among carriage barns, stables, and outbuildings scattered across the rolling terrain. But Ladd's most distinctive contribution began in 1908, when she opened Maple Cottage -- a large residence on the grounds -- as a convalescent facility where "deserving gentlewomen who are compelled to depend on their own exertions for support" could recuperate from illness, free of charge. It was charity with a precise social address: women who worked for a living and could not afford to rest. After Ladd's death in 1945, the convalescent mission relocated to the renovated main residence and continued under the Kate Macy Ladd Fund.

How a New Jersey estate ended up in the hands of Moroccan royalty is one of those stories that makes the Somerset County horse country feel less like suburban New Jersey and more like a crossroads of global wealth. Hassan II, King of Morocco, acquired Natirar and used it as a private retreat. Hassan II died in 1999, and the estate passed to his son, Mohammed VI. The estate remained in royal hands until 2003, when Mohammed VI sold the property to Somerset County. The sale price brought 491 acres of prime real estate into public ownership -- a rare transfer that preserved the core of the estate from the subdivision that consumed so many comparable properties in the New Jersey exurbs during the 2000s development boom.

Somerset County kept 404 acres as a public park but leased 90 acres -- including the mansion, carriage barn, and most outbuildings -- to local developer Bob Wojtowicz, who set about transforming the core buildings into a hospitality destination. The carriage house became Ninety Acres, a restaurant that opened in late December 2009, while an attached garage was converted into a cooking school. The mansion's transformation proved more complex. Wojtowicz first partnered with Richard Branson's Virgin spa brand, then pivoted to Miraval Resorts, and finally landed on Montage International, whose Pendry brand now operates the hotel. The decade-long courtship of hospitality partners speaks to the difficulty of adapting a century-old estate to modern luxury standards -- preserving architectural character while meeting the expectations of guests who can afford to stay anywhere.

The public portion of Natirar unfolds across an unusual geography: 247 acres in Peapack-Gladstone, 124 in Far Hills, and 40 in Bedminster. The North Branch of the Raritan River -- the waterway whose reversed name christened the estate -- runs along the southern boundary, while Peapack Brook threads through the interior. Lawns give way to woodland, and historic farm buildings dating from the mid-eighteenth through mid-nineteenth centuries dot the landscape, though most remain closed to the public. Walking trails follow the river corridor and wind through meadows that have been open land since before Kate Macy Ladd arrived with her whaling fortune. The park entrance sits near the spot where Main Street crosses the North Branch, close to the Gladstone Branch rail line -- a commuter connection that once brought New York's wealthy to their country retreats and still delivers weekend visitors to this improbable Somerset County crossroads.