No. 103: Jan-Feb 1996
We tend to think Mayan engineering only in terms of those impressive pyramids at Tikal, Copan, and many other sites, but they were accomplished builders of roads and bridges, too.
"Scientists working at the Mayan ceremonial center of Yaxchilan, Mexico, have discovered the remains of a sophisticated 600-foot-long suspension bridge built in the seventh century A.D. The bridge, which spanned the Usumacinta River, had massive concrete piers, a rope-cable suspension system anchored to stone mechanisms, towers, and a bed of hard wooden planks. It probably stood for 500 years above water 40 to 150 feet deep, with a steady current of 5 to 7 m.p.h., which increases to 10 to 15 m.p.h. at flood stage. Civil engineer and archeologist Jame O'Kon says the bridge was the world's longest until 1377, when a larger one was built in Italy."
(Anonymous; "Mayan Suspension Bridge," INFO Journal, no. 73, p. 44, Summer 1995. Source cited: Washington Times, February 26, 1995. INFO = International Fortean Organization)
Comment. One wonders why such a talented society collapsed so suddenly!