Inside New York City's Most Secret Basement

https://www.youtube.com/watch?v=qLPOmtI4W9I
Do you know what lies deep below New York's Grand Central Terminal? Almost no one who passes through every day has any idea what is underneath their feet.

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Wide bridges and tunnels

https://i.pinimg.com/originals/d5/3b/90/d53b906a3964fa21bcf4b6c8241c4bbe.jpg 

A wide bridge or tunnel can have 2 or a few sections which give it the extra overall width.

sf

Wednesday, February 6, 2019

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