While Puente del Inca has shown signs of deterioration, it remains stable under its weight under present conditions.[2]Factors of safety ranging from 1.5 to 3.0 have been estimated for the arch.[2]
^Scheffel, Richard L.; Wernet, Susan J., eds. (1980). Natural Wonders of the World. United States of America: Reader's Digest Association, Inc. p. 306. ISBN0-89577-087-3.