His neighbors aren't exactly revving up the welcome wagon. In 1998, they were sufficiently enraged by the idea of a house five times larger than their own to complain repeatedly to the Town of Southampton. They hired consultants to assess the potential impact of the Rennert mansion on the neighborhood, and they sued to stop the town from issuing building permits. The lawsuit failed, but the town has since passed a law limiting houses to 20,000 square feet.

The mansion, part of a 63-acre estate called Fair Field, is the largest on the East End and one of the largest in the United States. It encompasses several buildings and has 29 bedrooms, 3 dining rooms, 3 swimming pools side by side, a 164-seat theater and a recreation pavilion with a basketball court, gym and a 2-lane bowling alley.

Neighbors have expressed concerns that the mansion might become a resort or religious retreat, which might create traffic and environmental problems. They speculated that it might used as a hideaway for one particularly high-profile friend of the Rennerts -- Benjamin Netanyahu, the former Israeli prime minister and the current finance minister.

Until last week, Mr. Rennert, 70, had maintained a steadfast public silence, declining for years to talk to reporters or to address speculation about what might go on behind his thick hedgerows. But last Sunday morning, while sitting with his 25-year-old son, Ari, he described Fair Field as the place where he would spend his old age, surrounded by activity and family. Mr. Rennert and his wife, Ingeborg, also have two married daughters and one granddaughter. They also have homes in Manhattan and Jerusalem.

''I'm buying old age and loneliness insurance,'' Mr. Rennert said, chuckling as he waved a hand toward the mansion. He acknowledged that with 29 bedrooms, he could find plenty of company. ''I'm trying to convince him of that,'' he said, nodding toward his son, who smiled sheepishly.

Wearing track pants and running shoes, his tanned face framed by a leonine mane of white hair, Mr. Rennert sidestepped a question about the sort of relationship he expected to have with his neighbors. Then he briefly addressed reports that his estate would be put to uses other than as a single-family house.

''This has been done by just a few people with emotional and psychological problems,'' he said. ''And I don't want to get into that.''

He said he had no intention of using the mansion as a religious retreat or a resort and would not ever sell it. He would not say how much the mansion cost to build.

As for Mr. Netanyahu's living there, Mr. Rennert's public-relations consultant, Steven Rubenstein, said that Mr. Netanyahu was too busy in Israel to consider moving to the Hamptons. ''This is a home for the Rennert family,'' said Mr. Rubenstein, whose Manhattan firm, Rubenstein Communications Inc., also represents the Israeli Consulate in Manhattan. Mr. Rennert said he had good reason to maintain his anonymity: ''I have a wife and children I need to protect.'' Asked whether he was protecting their privacy, he shook his head almost imperceptibly but did not answer.

In its issue of Feb. 17, 2003, Business Week said that Mr. Rennert earned his first $500 million selling high-yield junk bonds in the 1990's and used that fortune to finance an private industrial empire held under the umbrella of his Renco Group. Through Renco, he owns AM General, the manufacturer of the supersize Hummer sport utility vehicles and the Humvee military vehicles.

Federal regulators and environmentalists have pursued Mr. Rennert, filing at least a dozen lawsuits, calling his smokestack businesses -- which make steel and produce magnesium, lead and coal -- some of the country's worst polluters, Forbes Magazine reported on July 22, 2002. ''Bondholders would like to tear him into many small pieces,'' Forbes said, adding that investors lost about $700 million on the $1.5 billion in bonds his companies issued from 1992 to 1998.

Whatever problems investors may have had, Mr. Rennert has been generous to Jewish and Israeli causes, bestowing the Rennert name on a women's Torah study program in Israel and endowing a chair in Judaic studies at Barnard College. He has also given large donations to Yeshiva University and the Center for Jewish History in New York.

Mr. Rennert said that he already had some pet charities on the South Fork but that because he is an Orthodox Jew who observes the Sabbath from sundown Friday to sundown Saturday, it might be difficult for him and his family to attend weekend benefits.

''I want a normal life,'' he said, adding that he did not want to seek publicity.

Fair Field, whose buildings cover about 110,000 square feet altogether, is unparalleled on the East End in sheer girth and luxury. The U-shaped mansion, covered in what appears to be buff-colored stucco, has two courtyards, each with a fountain, and is surrounded by English-style formal gardens, an orangery, guardhouses at the entrances and its own power plant.

Long Island has other huge houses, of course. Idle Hour, constructed in Oakdale for William K. Vanderbilt, had 110 rooms and 70,000 square feet. It is now part of Dowling College and is no longer used as a residence. Oheka Castle, in Huntington, completed in 1917 for Otto Kahn, has 72 rooms, including 25 bathrooms, and covers some 62,000 square feet. It is now a catering hall.

George W. Vanderbilt's estate in Asheville, N.C., completed in 1895 and appropriately named Biltmore, claims to be the largest private house in the United States. Its main mansion has 250 rooms covering 175,000 square feet.

Told of Fair Field's total of 110,000 square feet, Sarah Thomas, Biltmore's public relations coordinator, laughed. ''Wow,'' she said. ''That's probably as close as anyone's gotten to us in a long time.''

The neighbors' reactions to Mr. Rennert and his mansion have been mixed. William Tillotson, a Narrow Lane resident and co-chairman of the Sagaponack Citizens Advisory Committee, which acts as a conduit to the Town Board, said: ''It would be neat if he came to our meetings. He must have a point of view on something. But my guess is, we'll never see him. The butler will do all the shopping.''

While fishing last winter on Moose Head Lake in Maine, Mr. Tillotson said, he met an airplane pilot who described a recent flight over the South Fork. ''He said he saw some huge industrial project being built out here, with fields around it,'' Mr. Tillotson said. ''He was pretty surprised when I told him it was just a house.''

Although Fair Field is hard to miss, Jennifer Pike, who runs a farm stand on nearby Sagg Main Street with her husband, Jim, said she had not looked at it in years. ''I just don't notice it,'' Ms. Pike said. ''It doesn't bother me in the least.''

But Sandy Gross, who lives in Water Mill but bikes and swims in adjacent Sagaponack, said of the mansion: ''It's obscene and so excessive. Everyone wants to look at it it's like Versailles, but no one can believe it. It's arrogant.''

Donald Sachar, a citizens' advisory committee member, called the house ''an elephant in our living room, horribly intrusive.''

Other neighbors are resigned. On a recent Saturday afternoon, a woman named Gia -- she refused to give her last name -- was supervising two girls operating a lemonade stand across Daniels Lane from the Rennert estate. The mansion now obscures the second-story view of the ocean from her house, Gia said. ''We could have had 20 houses built on a property that size, but we only have one,'' she added, ''so we have to come to terms with it.''

Gia noted that Mr. Rennert had paid to repave part of Daniels Lane that was torn up by construction equipment being moved to his property, and she said that having such a wealthy family as neighbors could have its benefits.

According to town records, Fair Field, though not yet fully completed, already has an assessed value of $170 million and will owe $392,610 in property taxes this year. Of that, about $100,000 is earmarked for school taxes, representing nearly a tenth of the budget for Sagaponack's one-room school.

Mr. Rennert stressed that every aspect of the construction of Fair Field had complied with the law. When neighbors complained last year about his adding 4,000 tons of sand to raise the height of the dune that runs for about 1,000 feet between his mansion and the public beach, the town found that he had the requisite permits for that, too.

For some neighbors, the rise of Fair Field signaled the end of their resistance to the project. Kurt Vonnegut, the novelist, once famously announced that if Mr. Rennert were permitted to build, he would pack his bags and leave Sagaponack. Mr. Vonnegut did not return calls to his summer residence on Sagg Main Street, but his wife, the writer Jill Krementz, did. She said they were staying put.

''For a year, people were telling us they would miss us,'' she said. ''Thank God I own half the house. He can't sell it out from under me.''

She added that she hoped her outspoken husband would not comment further. ''I don't want him to say anything that will get us kicked off the guest list,'' she said, laughing. ''Maybe they'll ask us over to go bowling.''

Diane Louvel, who lives a short bicycle ride away in Wainscott, was sitting with two friends in front of the Sag General Store on a recent Saturday afternoon. Ms. Louvel said she had pedaled past Fair Field at every stage of construction and finds its completion anticlimactic.

''I don't think it's such a big deal, just a huge Italian villa,'' she said with a shrug. ''I guess it's just chateau envy.''

Harry Mumford, one of Mr. Rennert's closest neighbors, spends summers with his wife, Julia, in a tiny cottage just across Daniels Lane. He said Mr. Rennert had applied for permits to build a private home and that's what Mr. Mumford believes Fair Field will be.

''It's a whopper, but it's just a house,'' he said. ''I doubt the Rennerts would come over for a cup of coffee, but I'd have them. That's what neighbors do. Maybe I'll deliver a plate a brownies.''

Then he wondered aloud if the brownies would ever make it past the guardhouse.

Photos: CHATEAU ENVY -- Fair Field, Ira Rennert's 63-acre estate, has 29 bedrooms, 3 dining rooms, 3 swimming pools, a 164-seat theater and a recreation pavilion with a basketball court, gym and bowling alley. (Photographs by Doug Kuntz for The New York Times)(pg. 1); The gate to Fair Field on Daniels Lane in Sagaponack. There are guardhouses at each entrance. Ingeborg and Ira Rennert attended a fund-raiser for the Guggenheim Museum in December 2001. (Photo by Doug Kuntz for The New York Times); (Photo by Bill Cunningham/The New York Times)(pg. 6)

Iquitos Journal

Adopting Forebears’ Faith and Leaving Peru for Israel

Tomas Munita for The New York Times

Peruvian Jews celebrating the Sabbath at a synagogue in Iquitos

By SIMON ROMERO
Published: June 21, 2009

His dream, which he has vigorously pursued, is to persuade the descendants of Sephardic merchants who settled in this remote corner of the Amazon basin more than a century ago to reaffirm their ties to Judaism and emigrate to Israel.

“It is getting very lonely here,” said Mr. Reátegui Levy, 52, an inspector at Peru’s national oil company, referring to the more than 400 descendants of Jewish pioneers who have formally converted to Judaism this decade, including about 160 members of his immediate and extended family. Nearly all of them now live in Israel.

Until recently, such a rebirth of Judaism here seemed unlikely. The history of Jews in Iquitos, dating from the late-19th-century rubber boom that transformed this far-flung Amazonian outpost into a once thriving city of imported Italian marble and a theater designed by Gustave Eiffel, was almost forgotten.

But Mr. Reátegui Levy and a handful of others began organizing the descendants of dozens of Jews from places as varied as Morocco, Gibraltar, Malta, England and France who had settled here and deeper in the jungle, opening trading houses and following their star in search of riches and adventure.

The rubber trade collapsed, and fortunes here and downriver in the Brazilian city of Manaus vanished. Some Jewish immigrants perished young, succumbing to diseases like cholera. A few stayed, marrying local women and raising families. Others returned home, leaving behind descendants who clung to a belief that they were Jews.

“It was astounding to discover that in Iquitos there existed this group of people who were desperate to reconnect to their roots and re-establish ties to the broader Jewish world,” said Lorry Salcedo Mitrani, the director of a new documentary, “The Fire Within,” about the Jews of the Peruvian Amazon.

Scholars compare the Jews here with groups like the Hispanic crypto-Jews of the southwestern United States and northern Mexico, the Lemba of southern Africa or the Bene Israel of India, who in varying ways have sought to reclaim a Jewish identity that had seemingly been weakened through time.

“We were isolated for so many decades, living on the jungle’s edge in a Catholic society without rabbis or a synagogue, in which all we had were some vague notions of what it meant to be Jewish,” Mr. Reátegui Levy said.

“But when I was a child, my mother told me something that forever burned into my mind,” he said. “She told me, ‘You are a Jew, and you are never to forget that.’ ”

Iquitos lies four degrees south of the Equator, reachable only by boat or plane. Isolation, intermarriage and assimilation nearly wiped out the vestiges of Judaism here. Storefronts chiseled with Jewish surnames like Foinquinos and Cohen, and a cemetery ravaged by vandals, served as some of the few reminders of the community that once thrived here.

But by the end of the 1990s, some of these descendants, including Mr. Reátegui Levy, were brought together by Víctor Edery, a patriarchal figure who organized religious ceremonies in his own home, keeping a few customs alive even if it was done by blending Jewish and Christian beliefs.

Still, the existence of the Jews of Iquitos posed some philosophical challenges to some Jews elsewhere. Since nearly all the Jews who originally settled here were men, their descendants could not attest to having Jewish mothers, ruling them out as being Jewish according to strict interpretations of Jewish law.

Moreover, the Jewish community of about 3,000 people in Lima, the capital, largely preferred to ignore the Jews of Iquitos, some scholars say, in part because of the thorny issues that the Jews here posed about race and origins. This is, after all, a country where a small light-skinned elite still wields considerable economic and political power — and Lima’s Jews are often seen as an elite within that elite.

“The notion of a Jew who looks like an Indian and lives in a poor house in a small city in the middle of the jungle is, at best, an exotic footnote to the official history of Peru’s Jewry as Lima sees it,” said Ariel Segal, a Venezuelan-born Israeli historian whose arrival here in the 1990s to study the community also helped serve as a catalyst for the Iquitos Jews to organize.

By the start of this decade, the Jews here were gathering to observe Shabbat each Friday and during the High Holy Days at the home of the patriarch, Mr. Edery. After he died, they met on Próspero Street at the home of Jorge Abramovitz, 60, whose father, a Polish Jew, moved here long after the collapse of the rubber boom.

While they lacked a rabbi, they conducted services in Hebrew they learned from cassette tapes. They cleaned their cemetery and began burying their dead there again. They persisted in their campaign to be recognized as Jews and to be allowed to emigrate to Israel.

Finally, they persuaded Guillermo Bronstein, the chief rabbi of Lima’s largest Ashkenazi synagogue, to oversee two large conversions, easing the way for hundreds to move to Israel. The exodus included nearly the entire Levy clan, descended from Joseph Levy, an adventurer who put down stakes here in the 19th century.

Mr. Reátegui Levy, the oil field inspector, moved in 2005 with his wife and six children to Ramla, a dusty city southeast of Tel Aviv. But despite dreaming for decades of such a move, he said he had trouble adjusting to Israeli life.

He said he missed his house with cacao and passion fruit trees, and the status of being a manager at PetroPerú. He murmured something, just audible over the din of this city’s thousands of motorcycle rickshaws, about losing the spark of love with his wife.

So, unlike nearly all the Iquiteños who moved to Israel, Mr. Reátegui Levy moved back, alone.

He still attends Shabbat at Mr. Abramovitz’s home each week, along with 40 or so other regulars who dream of formally converting and moving to Israel. While their numbers have dwindled, he encourages them and regales them with tales of fertile land in the Golan Heights and the bravery of his eldest son, Uri, who is in the Israeli Army.

But something keeps Mr. Reátegui Levy here in Iquitos, the same decaying jungle city that attracted his great-grandfather from Tangier so many decades ago. “My family, my heart and soul, all that I hold dear are in Israel,” he said. “Maybe I am back here for a reason.”

This article has been revised to reflect the following correction:

Correction: June 26, 2009
The Iquitos Journal article on Monday, about the Jews of Iquitos, Peru, a decaying Amazon jungle city that thrived as a 19th century trading post before the decline of the rubber business, referred incorrectly to the location of Manaus, Brazil, another Amazon jungle city that suffered when the rubber business weakened. It is downriver from Iquitos, not upriver.

Tomas Munita for The New York Times

Ronald Reátegui Levy, a Jewish oil field inspector, has persuaded many Jews in the town to move to Israel.