(CNN) For 50 years, residents of a New Hampshire town speculated what might be inside a time capsule from 1969. Moon-landing memorabilia? Local artifacts from the era? Perhaps a letter to the future?

Turns out, they're all wrong: The capsule was empty.

For years, the unopened safe sat on a dusty shelf in a Derry library. In honor of its 50th anniversary, library director Cara Potter decided to find out what it contained before its public reveal, CNN affiliate WMUR reported.

Flanked by a small crowd of local historians and town officials, Potter opened the capsule. It took a few tries to get the old door free, but once it was, the group was disappointed by what they did -- or rather, didn't -- find.

"We were a little horrified to find there was nothing in it," Potter said.

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