Right outside the (really, really good) Grand Central Oyster Bar and Restaurant is the incredibly fun and weirdly awesome Whispering Gallery. Visitors can carry on hushed conversations from opposite sides of the room as if they were standing next to each other (if you try it, you might want to be careful about what you're whispering). The arched design and glazed tiles carry the sound waves via the room's perfect acoustics, and the construction's a popular spot for marriage proposals if you're in the market for a place to pop the question.