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.