The National Park Service is celebrating its 100th anniversary this year, and the folks at Gettysburg National Military Park want to remind you not to take any stones from the park. Why? Well, for one reason, they’re cursed.

That’s according to a blog post by Maria Brady, a park ranger at Gettysburg.

Brady writes that the park sometimes gets packages in the mail with people returning rocks they took— which is a violation of federal regulations and can result in $130 worth of fines and fees, she points out— and those packages usually have letters.

In one letter, sent to Gettysburg in May, a man admits that he and his wife took three stones. “We didn’t know then how the removal of those stones would affect our lives and we didn’t know they were cursed,” he wrote. The man then explained that he lost his wife, son, his job, and then went to prison.

In another letter, received last year, a repentant person explains that he or she is sorry for taking stuff from the site in 2006. “Since then I’ve had nothing but horrible times, injured on the job, several surgeries, relationship failures, etc…” the person writes.

So, don’t take any rocks, Brady writes. It’s wrong, and could affect the park, since over a million people visit it annually, she says, and if everyone took something, that would be a real problem, especially for the place’s historic stone walls.

Also, you might get cursed, she warns.

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