This weekend marks a milestone for Little Free Libraries — they're those little boxes filled with books that you see along sidewalks, or in people's front yards.
From humble beginnings in Hudson, Wis., the Little Free Library movement now reaches around the world, and it's celebrating its 10th anniversary.
Each Little Free Library has its own unique flavor. Some look like replicas of Gothic churches; others are modeled after snails. But they all have the same purpose: sharing the love of reading. It's sort of like the "take a penny, leave a penny" model — but for books.
• From 2015: Little Free Libraries find global following
The idea was started by Minnesota native Todd Bol. It was a way for him to honor his late mother, who was an educator and a big reader.
Using some wood from a garage remodeling project, Bol built a replica of an old schoolhouse, put some of his mom's books in it and stationed it on his lawn in Hudson — hoping his neighbors might find new life for some of her old books.
Margret Aldrich, the media and programming manager of the Little Free Library nonprofit, described what happened next.
"When Todd put out that first Little Free Library, he wasn't sure what would happen. And when he saw how his neighbors reacted to it — they were excited, they would stop and have conversations, they would linger, share books — he thought there was a little piece of magic there, and he really wanted to share that with the rest of the world," she said.
Since then, the little free library project has expanded around the globe.
Today, there are over 80,000 registered Little Free Libraries in places ranging from Window Rock, Ariz., to Khartoum, Sudan.
Bol died of pancreatic cancer last year, but his project lives on. Aldrich said about 120 million books have been shared so far.
"I think Todd would be so proud that we've reached the 10th anniversary for Little Free Libraries, and really to see that this momentum keeps growing," she said.
To celebrate its 10th anniversary, the Little Free Library nonprofit is hosting an event this weekend called "The Big Share." They're asking people around the world to share a book at a Little Free Library, snap a selfie and post the photo on social media with the hashtag #LFL10.