Anything that ends with -henge tends to be shrouded in weirdness and mystery, but “Ponyhenge” in Lincoln, Massachusetts, might just be our new favorite. As its name suggests, Ponyhenge is a collection of plastic ponies and rocking horses sitting pretty (and nightmarish-ly) in a field about 14 miles west of Boston. The first ponies started appearing sometime around 2010; over the years, the collection has grown exponentially and will frequently rearrange into circles and rows. How did the first pony appear? Who adds and organizes the collection? Do the ponies come alive when we're asleep? No one knows. It’s Ponyhenge.