Mapparium whispering gallery

The Mapparium is a three-story stained-glass globe inside the Mary Baker Eddy Library where the interior functions as a whispering gallery: sounds travel along the glass so whispers on one side can be heard clearly on the opposite side. The painted-glass globe was installed in 1935 and is reached via guided visits and tours. It is an unusual acoustic and visual exhibit tucked inside a library building rather than a standalone museum.