Step into, say, Little Odessa in New York City, where the sidewalks are flecked with caviar stands and the signs are in Russian, and you might feel like you’ve left the country. But there truly is a way to leave the United States while in midtown Manhattan (although with fewer blintzes): Clear security and enter United Nations headquarters.

Many people don’t realize that the U.N. is actually an international territory. It’s defined as an “extraterritoriality,” meaning that it’s exempt from any local law. As the U.N. explains [PDF], “No federal, state or local officer or official of the United States, whether administrative, judicial, military or police, may enter UN Headquarters, except with the consent of and under conditions agreed to by the Secretary-General of the Organization.”

The history of how this surprise international territory came to be is fascinating. Sovereignty was a political hot topic at the time the U.N. was established, just after World War II in 1945. To provide neutral ground, the Canadian government offered to donate its Navy Island in the Niagara River, a body of water that marks part of the U.S.-Canadian border.

But two months after the U.N. was formed, Congress voted to invite the organization to base itself in the U.S. That’s when more than 200 sites around the country started jockeying to hold the new headquarters, as Rutgers history professor Charlene Mires recounts in her book Capital of the World: The Race to Host the United Nations.

Out-of-the-way spots like the Black Hills of South Dakota pushed to be considered. Mires summarizes the competition this way: “At times it seemed the world’s diplomats could agree on only one thing: under no circumstances did they want the United Nations to be based in New York.”

In the end, only an unexpected $8.5 million donation from the Rockefeller family placed the headquarters in expensive, logistically complex New York City. The gift was especially toward purchase of nearly 18 acres of Manhattan land overlooking the East River, then a rundown industrial area of slaughterhouses and a railroad barge landing. The Rockefellers owned an apartment building across the street.

If you’re thinking, “Great! If I ever need to flee the U.S. authorities I’ll try there for safe haven,” be warned. U.N. officials seem to have sewn up every potential corner in a patchwork of laws. They established their own firefighting department, security force, and post office branch (although New York City services are also occasionally used). And they put out explicit rules about avoiding jail: “The United Nations is bound by an agreement with the United States, its host country, to prevent its Headquarters from being used as a refuge for persons attempting to avoid arrest under the Federal, State or local laws of the United States,” they say. “People being extradited by the United States Government are also denied use of United Nations Headquarters in attempts to avoid arrest.”

There’s no record of anyone trying to give birth in U.N. headquarters with hopes of a birth certificate reading "international territory" (the way occasionally expectant mothers are said to try on planes). The closest anyone seems to have come is a baby delivered a couple blocks away, by a cop during morning rush hour on FDR Drive earlier in 2016. And there’s been seemingly no major crimes committed in an attempt to thwart American justice—the most violent events the headquarters appear to have seen occurred in 1964, when a bazooka was fired across the East River during a speech by Che Guevara and a woman tried to charge into the building to stab him.

For New Yorkers who hate the traffic snarls and diplomatic license plates that major U.N. gatherings entail, know that some of the diplomats hate the location, too. Montreal and Dubai have been offered up as potential new headquarters sites—but since the U.N. just remodeled its headquarters in the past few years, don’t look for New York City to lose its 18 acres of international territory anytime soon.