In Brasilia, Brazil.
At the National Cathedral.
I’d never heard of a “whispering wall” until I came across this one during a trip to the capital of Brazil.
So, if you don’t know, a whispering wall serves as a way for people in a church to talk to each other at long distances without raising their voices above a whisper.
Person A would stand where I took this picture and whisper a message with his or her lips along the wall.
Person B stands at the next opening segment in the wall (in this pic, the black square beneath the blue glass) and hears what Person A whispered as if they were standing rightnext to each other.
The curves and blocks, white shiny marble, and the rich blue stained glass make for a nice shot.