the west bank of the Hudson (north river inside of NYC, and this area is) is called the Palisades-- (some old timers will remember an early 1960's R & R hit Palisades Park, named for the same) is a basalt layer that was layed down long, long ago(help me whitman, back in the days of tex rex i think) .. and Up ended -- so it is now perpendicular. it too has the same hexogon crystaization-- but not as regualar as the giants causeway.
the Palisades were being mined for trap rock, and the Rockefellers bought up most of the land, and donated to the state- provide it was made it into parks--there is a Palisades parkway, and rugged trails between the two main parts of the park, Apline landing and Stateline park (the state line of NY/NJ. Most of the park is in NJ. the there is an other out cropping up state.. (a german/dutch name, skrunks? for short?) famous place for rock climbing...
what is nice is they are not quite perpendicular-- but off by 10 to 15 degrees or so.. (not 90, but 80 to 75 degrees. just enough of a slope that you can climb them.. (well i could and did in my youth.. now i am way to much out of shape.) but steep enough to seem almost straight up!
