Few museum exhibits can say they turn the world inside out. And yet that's exactly what happens at the Mapparium, The Mary Baker Eddy Library's most famous sight. Its three-story-high stained-glass globe is emblazoned with a map of the world in 1935, meant to be viewed from the inside. After guests enter the globe through a gangway, glittering LED lights bring its bright, vibrant colors to life during a presentation on the history of ideas and their spread throughout the world. Another bonus: the acoustics of the globe make it a whispering gallery, meaning that visitors standing at either entrance can communicate with each other by speaking in a low voice or burping a message in Morse code.