Riddles in the Dark - What has roots as nobody sees...

Riddles in the Dark - What has roots as nobody sees... (23rd street station; uptown N, R, 1 train)

Riddles in the Dark - What has roots as nobody sees... (Barclays Center/Atlantic Ave station; Manhattan bound N, R, B & D trains)

Riddles in the Dark - What has roots as nobody sees... (Broadway-Lafeytte street station; uptown B, D, F & M trains)

Riddles in the Dark - What has roots as nobody sees... (28th street station; downtown 1 train)

Riddles in the Dark - What has roots as nobody sees... (59th street/Columbus Circle station; uptown 1 train)

Riddles in the Dark - What has roots as nobody sees... (42nd street station; uptown 1, 2 & 3 trains)

 Riddles in the Dark - What has roots as nobody sees... (14th street station; uptown 1,2 & 3 trains)

Riddles in the Dark - What has roots as nobody sees... (59th street/Columbus Circle station; downtown A, B, C & D trains)

 Riddles in the Dark - What has roots as nobody sees... (Bergen street station; Brooklyn bound 2 & 3 trains)

Riddles in the Dark - What has roots as nobody sees... (2015)

Answer: The Mountain.