[woodbutcher1963]

That is my understanding too. If you look at the old maps of Manhattan, from the 1700s there was a wet area where Greenwich Village is now. That is why all the buildings are only 4 stories tall.

Unlike the Back Bay section of Boston where there was rock underneath that water in the Charles River. Which is why the John Hancock tower and the Prudential building are there.

I remember walking from the USS Intrepid on the West Hudson River back up to the Hotel Penn on the south side of Macy’s between 6th & 7th avenue. It is surprisingly UP hill in elevation to the middle of the island.

[SamAdams76]

I believe you are referring to the old Collect Pond. The below is a rendering of what it might have looked like during the Colonial era. Hard to believe Manhattan used to be so pastoral.