Even in today’s troubled real estate market, the challenges facing Updown Court stand apart.

A 50,000-square-foot English estate originally designed to resemble a Middle Eastern palace, Updown Court took 18 years to construct, with the last flourishes added in 2005. Among other features, the estate boasts 103 rooms (including 27 bathrooms), a 30-person home theater, five pools, a guesthouse, a gatehouse, a squash court, a snooker area, a tennis court, and a stable. (View a slideshow of more multi-million dollar homes that can't find a buyer.)

But the home’s most outlandish feature is surely its price tag: $139 million. That figure makes it both one of the highest-priced houses ever built on spec (without a committed buyer) and one of the world’s most ungainly white elephants. It has yet to attract a single acceptable bid in three years on the market. Its original developer went to jail. The new developers, Leslie Allen-Vercoe and Alan Mackinnon, both Britons, have tried in vain to unload it by periodically making changes in the hopes of attracting billionaires of different nationalities. The British tabloids have dubbed it the “house of horrors.”

Selling Updown Court wasn’t supposed to be this hard. When Allen-­Vercoe bought the unfinished estate out of receivership for $40 million in 2002, Middle Eastern wealth was well ensconced in London. The duo even hoped that Sheik Mohammed bin Rashid al-Maktoum of Dubai, who has a summer home across the street, might make a bid (he never did). Allen-Vercoe’s plan was to borrow an extra $70 million, finish the place, then let the bidding begin.

But as the real estate landscape shifted, so did the execution of the blueprints. To catch the eye of the newly wealthy Russians who started moving to Britain, the men refashioned a gilded sultan’s throne room, adding heavy wood paneling. They also installed a spiral staircase modeled after the one in designer Gianni Versace’s Miami Beach mansion, a marble mosaic of Mount Fuji, and a heated marble driveway. The American architect was replaced, and a bevy of Italian workers were imported to make the bathrooms more European.

The construction drew so much attention that the estate was featured on a VH1 program, where it inspired a high-schooler from Missouri to form an Updown Court Facebook group (among those posting: George Penza, who says he is the mailman for Updown Court).

“At the end of the day, you can’t make anyone buy it,” says David Carter, a director at Country Houses U.K. for Hamptons International, one of the listing agencies representing Updown Court. He adds that there has been little domestic interest. And that’s putting it mildly. “It has more of an international flavor, so it’s not really worked from the English-buyer point of view.”

Even in the best of times, there are rarely more than a handful of lavish spec houses available around the world, and those are usually priced at less than $50 million. But a boomlet in projects a few years ago, when the market was going strong, has produced something of a glut—just as prices are weakening. Updown Court also has its own history working against it. Two decades ago, the property was just another empty megalot in Surrey. The home that had stood on it burned down, and a local engineer, Anthony Pearce, acquired the land with the dream of building a Middle Eastern-style palace on it. His blueprints called for three acres of marble and lots of round rooms, but the full design was never realized. In the middle of construction, British Customs charged Pearce with money laundering, and in 2001, agents descended on the property, arresting and jailing Pearce.

Allen-Vercoe helped Pearce arrange the initial financing and then bought Updown Court for approximately $40 million—including about $10 million of his own funds (the money went to creditors). He also bailed Pearce out of jail. After an 18-month trial, charges against Pearce were dropped, but the experience left him so bitter that he immigrated to Wilmington, North Carolina, where, according to Allen-Vercoe, he still lives. (Pearce did not return calls.) To resume construction, Allen-Vercoe borrowed another $70 million and partnered with Mackinnon, who didn’t contribute funds but agreed to act as estate manager.

Though the market for prime British real estate has recently been flat, Allen-Vercoe and Mackinnon are full of Panglossian bluster about Updown Court’s prospects. Sitting in the estate manager’s office near the house’s entrance, the duo are having biscuits after a rare client viewing. (They decline to say who it was.) A high-school dropout from suburban London, Allen-Vercoe is dressed dapperly in a gray pinstripe suit, a pink, blue, and red striped tie, and black ostrich loafers. He says he worked his way up in residential real estate. Mackinnon, the more understated of the two, made money in commercial real estate in Germany and Latvia.

Though they were relying exclusively on professional real estate agencies to handle marketing, Allen-Vercoe and Mackinnon recently decided to also promote the estate themselves—an initiative that, if successful, could save them a 2 to 3 percent commission fee. “I’ll read about some billionaire who’s done something successful, and I’ll drop him a line,” Allen-Vercoe claims, in what is either a bit of hubris or hyperbole. “I’ve traveled around, and I’ve met people in fairly influential positions, so I’ll contact them.”

Out of six showings during the past three weeks—up from only two or three in the first six months of the year—at least two potential clients have surfaced, according to Allen-Vercoe. One is “a Far Eastern royal family,” he says; the other he identifies only as a group looking to purchase Updown Court as a time-share.

Allen-Vercoe is opposed to adjusting the price to reflect market conditions. “I would never lower the price,” he says with his arms crossed, “but I have thought of raising it.”