That's right ... the L.A. estate known as Chartwell -- best known for being featured on "The Beverly Hillbillies" -- is off the market, and the mansion's new owner is Rupert Murdoch's son, 48-year-old Lachlan.

The real estate transaction is not only the most expensive in L.A. history but in the history of the entire state of California. And, get this ... it sold for $200 million LESS than the initial asking price.

Chartwell was listed off-market about 2 years ago at an astronomical $350 million but dropped to a slightly more affordable $245 mil when it entered the multiple listing service. The price dipped again to $195 mil this summer, before reportedly being sold to Lachlan for the cool $150 mil.

It's now the second priciest home sale in the U.S. ... trailing only the $238 million NYC penthouse purchased by hedge fund billionaire Ken Griffin in January.

The exterior was used for the credits of the legendary '60s show ... and it's become a tourist destination ever since, where people peer through the gates to get a look. The estate boasts a 25,000-square-foot main house, a tennis court, a guest house, and of course -- a cement pond ... and another house to go with that.

There are also acres of gardens with tall hedges and trees for privacy.

BTW -- Chartwell is actually located in Bel-Air, not Beverly Hills, and was last owned by late billionaire A. Jerrold Perenchio, the chairman of Univision. The new owner is cochairman of his family's company, News Corp.