For about 300 years, thousands of “dead letters” have been sitting in a waterproofed trunk in the Netherlands. They were originally held there by postmasters in The Hague who believed that maybe, just maybe, someone would come looking for them someday.

The contents of those correspondences are finally being read and brought back to life through the “Signed, Sealed & Undelivered” project. The 2600 pieces of mail—600 of which are still unopened—were sent from all around Europe between 1689 and 1700. The letters were acquired by the Museum voor Communicatie in 1926, having previously been in the possession of Simon de Brienne and wife Maria Germain, who were postmasters in The Hague until 1707.

The intent of collection wasn’t exactly sentimental—at the time, recipients paid for letters upon delivery, and the postmasters hoped they might collect the fee if people eventually wanted to retrieve the notes.

Letters went undelivered for all sorts of reasons, from absent recipients to outright refusals. One in the archive, marked niet hebben, was one of the refused. It’s a letter written by the friend of an opera singer and addressed to a wealthy merchant in The Hague, likely the father of the singer’s unborn child.

It reads: “I am writing on behalf of your friend and mine and she realized as soon as she left the opera company in The Hague to go to Paris that she had made a terrible mistake. Now she needs your help to come back to The Hague. I could tell you the true cause of her pain, but I think you can guess.”

The letters are an invaluable glimpse at life during that particular place and time. The international team is able to study the varied lives of everyday people with no filter whatsoever. They contain six different languages offering valuable linguistic snapshots, and reflect much of what was happening at the time including political unrest, religious persecution, and violence.

The letters will be scanned and read without breaking the seals, allowing modern researchers to glean a bit of valuable history, while simultaneously preserving it.

Explore the gorgeously photographed letters yourself at the project’s website.