1.

"Bird´s eye view of the Manhattan of 1950 with its ranges  of Skyscrapers over transportation lines and the mountainpeaks of industry over each entrance"

From" Manhattan 1950" Raymon Hood

2.

A total of 38 mountains are positioned on the intersections of alternate avenues and the wider streets of the Grid, roughly every ten street. The bulb of each mountain exceeds the size of a single block

From "Delirious New York" R. Koolhaas, 1976. (p 177)

3 (txt).
mountain: You can be in the southern medow, in the lake, in the reservoir... watch behind the trees, in the background, don't you see them?

4.

5.

6.