After his death, Mr. Hughes’s $400 million estate was put in a trust for his son, now in his late 20s; the terms allowed him access at age 35. Then, in 2004, after a confusing battle for trusteeship involving accusations of mismanaged funds, t he Mark Hughes Trust entered into an arrangement with Chip Dickens, a real estate investor in Atlanta; the trust lent his firm $45 million dollars to sell the land .

But Mr. Dickens couldn’t sell it, even with the help of his partner Victorino Noval — a philanthropist who served time in federal prison after pleading guilty to tax evasion and mail fraud in the late 1990s — and the debt owed to the Mark Hughes Trust ballooned to $200 million.

In 2016 the property was transferred to a company managed by Mr. Noval’s son, which also failed to sell the land. The Hughes estate then forced the foreclosure auction, on Aug. 20, and was the only bidder, offering $100,000.

That seemingly bargain-basement price came with a condition: that the estate forgive the $200 million loan. Any other buyer would have had to pay at least $200 million at auction to cover the debt.

The Mark Hughes Trust did not respond to requests for comment on the future of the place.

The plot is remote. It sits at the top of a road off Benedict Canyon, the same canyon that branches into Cielo Drive, known for the house where followers of Charles Manson murdered Sharon Tate and four others.

Like many mansions in the Los Angeles canyons, the Mountain feels eerily isolated, particularly because it dead-ends into its own private cul-de-sac, practically in the sky. Winding one’s way up to the peak ends in confrontation with a fortresslike gate that conceals the property entirely from view.