Really, you can’t bring guns into the 9/11 Memorial?

A tourist from Tennessee waltzed into one of the most secure sites in the city — and politely asked a cop if she could check her weapon.

Instead, she was dragged out in cuffs.

Now, Meredith Graves, 39, is facing at least three years in prison for thinking New York’s gun laws are anything like those in the Bible Belt.

Graves, a fourth-year medical student, showed up at the memorial on Dec. 22 to pay her respects during a trip north for a job interview.

She didn’t realize that the loaded .32-caliber pistol in her purse would be a problem until she saw a sign at the site that read, “No guns allowed,” sources said.

“She remembered she had the gun on her,” a source said. She walked up to a security guard and said, “I have this gun. Where can I check it?”

The guard told her that she was in luck because of “law enforcement day” — and led her to another area.

When she got to that section, she asked another cop, “We have this gun — can we check it in here? We [my husband and I] are not law-enforcement.”

That’s when she was arrested.

Graves, who has a full legal carry permit in Tennessee, was locked up on a weapons-possession charge and held on $2,000 bond that she posted yesterday. She is due in court on March 19.

She’ll soon find out exactly how serious New York City is about illegal guns. The Manhattan DA’s Office is pursuing a conviction on felony gun possession — carrying a minimum sentence of 3 1/2 years.

Mayor Bloomberg, with the help of the five district attorneys, has crusaded against the flow of illegal guns, especially from the South.

Out-of-state weapons have been used in a slew of homicides, including the murder of NYPD cop Peter Figoski on Dec. 12.

Sources don’t believe Graves’ intentions were sinister.

She and her husband, Richard Disharoon, drove to New York because Graves, a registered nurse, had an interview for a residency at Brookhaven Memorial Hospital on Long Island, sources said.

“You’d think states would reciprocate with the Second Amendment. She has a license to carry in Tennessee,” said her mother-in-law, who lives in Manchester, NJ.

“Everyone down there carries, and she just forgot,” said the woman, who would not give her name. “She was being honest, and this is the treatment they give innocent people.”

Graves, who has no prior criminal record, could not be reached for comment, and her Legal Aid lawyer did not return calls.

The case resembles the ordeal of Jonathan Ryan, a Florida man who was arrested for gun possession in 2010 after driving up north to help his girlfriend move — and ended up beating the rap at trial.

Ryan’s lawyer, Mark Bederow, said yesterday New York’s gun laws are too tough on people like Graves and his client.

“There may be technical guilt in some of these cases, but the law is not designed to deal with them,” he said.

Meanwhile, a loaded .38-caliber handgun was discovered Tuesday on the ground near the metal detectors at the memorial, sources said.

Additional reporting by Philip Messing