Literature Reference: The early coolness arises by the northern railing, as the lingering sunlight falls on the eastern fence. Source from 'Chi Shang Zao Qiu'.
北: Direction, in the morning facing the sun, the side to the left hand, opposite to "south".
槛: Threshold, the boundary of a doorway.
Meaning: The northern railing symbolizes tranquility, serenity, and harmony with nature.