Welcome to one of the most layered corners of Boston. You are on Tremont Street, near where it meets School Street, standing beside a stone church and the oldest graveyard in the city. Both are stops on the Freedom Trail, and together they pack nearly four centuries of colonial, revolutionary and religious history into a few steps. Here is a detail that surprises many visitors. The burying ground came first. It was founded in 1630 as the first graveyard in Boston proper, and for 30 years, from 1630 to 1660, it was the only burial site in town. The chapel arrived later, squeezed onto a corner of land that was already full of Puritan graves. As we walk through this guide, we will look at the graveyard and the people resting in it, then at the chapel's elegant Georgian architecture, and finally at how a church built for the Crown became the first Unitarian congregation in the nation. The names can be confusing, so keep this in mind: despite what it is called, the burying ground has always belonged to the city, not to the church.