After 113 years, historians are about to unlock what appears to be a time capsule once tucked away inside one of Boston’s most iconic copper statues.

The Bostonian Society announced Tuesday it had confirmed the long time rumor that a capsule from 1901 was hidden in the head of a lion statue atop the roof of the city’s historic Old State House. The lion was taken down for preservation work, which is when conservator Robert Shure decided to check it out — threading a fiber optic camera through a hole in the lion’s head where he found a small copper box, ABC News reported.

Heather Leet, the society’s director of development, told the Associated Press that the society first learned of the time capsule several years ago from a woman who was a decedent of the sculpture’s creator.

“She had a letter from him and a list of things in the time capsule,” she said.

The note mentioned things like letters from city leaders and campaign buttons from Theodore Roosevelt and Rutherford B. Hayes, according to the society, which runs the museum at the Old State House.

Then historians found a 1901 newspaper clipping the Boston Globe reporting that a small copper box, which had just been built by a coppersmith, was about to be hidden there. The article, titled “Lion and Unicorn: Copper Box to be Placed in Head of the King of Beasts,” said it would contain “contributions from state and city officials, the Boston daily newspapers, the name of the maker of the lion and unicorns, and others, which will prove interesting when the box is opened many years hence.”

Despite the article, this week’s discovery was still a surprise.

“There were a lot of people who didn’t think it was going to be there,” the society told ABC News. “We’re pretty confident after seeing the camera footage of the box.”

The copper lion statue, along with a unicorn statue, have a deep history with Boston’s Old State House. The first lion was hoisted to the top of the building in 1713 to symbolize the union of England and Scotland, Leet said.

That building, said to be one of the oldest public buildings in the nation, was built to house the government offices of the Massachusetts Bay Colony. It was the site of the Boston Massacre in 1770. Its balcony served as a stage during the reading of the Declaration of Independence in 1776. And sometime during its history, the statues were destroyed and replaced with new ones in an effort to preserve the building’s appearance.

The Bostonian Society said it hopes to retrieve the time capsule as early as next week and put the contents on display — if they’re not too fragile.

After the statue is restored, a new time capsule will be hidden inside.