An early edition of one of the world’s most famous documents, the Magna Carta, was unearthed in a pretty unexpected place – a scrapbook. Mark Bateson, a Kent, U.K.-based archivist, was tasked with looking for a charter from the town of Sandwich when he stumbled upon the rare find. He came across Sandwich’s Charter of the Forest in a Victorian-era scrapbook in the Kent County Council archives that just happened to also contain an edition of the groundbreaking document that dates back to 1300, the BBC reports.

This edition could be worth up to $15 million and is a very significant find, according to experts.

The find comes months before the 800th anniversary of the sealing of the document that established the principles of the rule of law. The first copy of the Magna Carta was drafted by the Archbishop of Canterbury on June 15, 1215. It was written to establish peace between King John of England and a group of rebel barons. Among the sanctions established by the law the Magna Carta ensured protections of church rights and limited feudal payments to the king.

The document found in Sandwich is not pristine – it was ripped and about a third of it was missing. Despite this, it is a rare and valuable find. The only other copy that dates back to 1300 is owned by Oriel College at Oxford University.

According the BBC, there are 24 known editions of the Magna Carta in existence.