Ever since the remains of over 900 burials were moved in 1897 to make way for the Tremont Street Subway, this little-known mass grave in the southern corner of the Boston Common has been home to all manner of unusual sighting.

Since the 1720s, thousands of people had been buried in what would later become known as the Central Burying Ground. But when Boylston Street was extended past there in 1836, the city engineers ran it right over a section of the graves. It’s more than ironic, really: the Burying Ground, or at least part of it, got buried. After the skeletons were discovered in 1897, they were all moved to a mass grave, which is still nearby. A faceless girl is the most common sighting among the gravestones.