The Magicians
Waterfall beneath Castle Whitespire
The gang walks past a waterfall and up to the front of Castle Whitespire in their search for the armory in episode 2x01 “Knight of Crowns”.
Source: Chris Fisher — Instagram, 2, 3
Mountain of Ghosts (waterfall)
The guide leads Alice and Eliot past a waterfall on their way up the mountain in episode 5x03 “The Mountain of Ghosts”.