Yaxchilan: The Labyrinth [January 3, 2004]
"On the right side of the passage a row of shallow niches opened, housing short masonry benches (beds?) under peaked, "corbel-vaulted," ceilings. (In corbeling, a series of stones, each projecting a little farther than the last, rises to a peak, spanning an opening in a primitive kind of arch.)"
Christopher Shaw, Sacred Monkey River: A Canoe Trip with the Gods, p. 271-2