Note VI-15 — Chapter VI · ANTIQUITIES OF TABASCO AND CHIAPAS, RUINS OF PALENQUE.
Reading edition
Stephens, vol. ii., p. 316; Waldeck, p. vi.; Charnay, p. 425, phot. 22. Dupaix's plate xiii., fig. 20, showing a section of the whole, indicates that the interior may be filled with earth and small stones.