The Red Room.
The Red Room, also known as "the waiting room," is an anomalous extra-dimensional space connected to Glastonbury Grove in Twin Peaks' Ghostwood National Forest. First discovered as early as the 1800s, the red room was believed by many to be the Black Lodge of local Native American legend. Many spirits appeared to "live" in the red room, most notably one calling itself "the arm."
Description[]
The red room was more accurately a set of seemingly infinite rooms and hallways, the only walls being the thick red velvet curtains that marked the division between different sections. The curtains' height and anchor were unclear. In one instance, the curtains lifted to reveal an endless black expanse beyond, the patterned floor stretching out into nothingness.
The floor was covered in a distinctive, alternating off-white and dark-brown chevron pattern. It was composed of a hard material, although in one of Dale Cooper's dreams, it was instead a patterned carpet. On one occasion, the arm's doppelganger somehow caused the floor to shake and break apart, revealing a body of water underneath.
Generally speaking, earthly laws of physics did not necessarily apply within the red room, as its arrangement could change from moment to moment, making navigation or escape extremely difficult. The passage of time was equally nebulous; Dib and Mandy appeared to be present in the room in a dream of Laura Palmer over a month before they actually entered it.