Mapparium (Mary Baker Eddy Library)

The Mapparium is a three-story stained-glass globe inside the Mary Baker Eddy Library that visitors can walk through. Completed in 1935, its panels depict the world as it was politically in the mid-1930s. The structure is noted for unusual acoustics: whispers spoken into one side can be heard clearly on the opposite side. The Mapparium is preserved as an architectural and cartographic exhibit open to the public by timed entry.