The Whispering Gallery in Grand Central Terminal is located in front of the Oyster Bar & Restaurant.
Just a quick history: The Grand Central Terminal was constructed in 1913 and is the world's largest train station and definitely one of the most famous ones (being featured in several movies).
The place owned a mystifying acoustic property: when two people stand at diagonal arches and whisper, they can hear each other's voices "telegraphed" from across the 2,000 sq-foot chamber.
But the question still remains: "Was it constructed with the intention of producing the acoustic effect?"
Location: 87 East 42nd Street