Ten Lost Roman Wonders: The World's Longest Tunnel, Tallest Dam, Widest-Spanning Bridge & More

"Apart from a few bridges that still work, the infrastructural achievements of the Roman Empire exist, for us, mostly as ruins. With a little imagination, those historic sites give us a clear enough sense of the empire's sheer might, but if we want to go deeper, we should then look into the numerous Roman constructions that haven't survived at all. In the video below from his channel Told in Stone, ancient-history YouTuber Garrett Ryan gives his personal top seven "lost Roman wonders," beginning with Trajan's Bridge, whose length of more than a kilometer across the Danube made it the longest bridge ever built at that time: a project of ambitions befitting a man that history remembers as one of the "Five Good Emperors.""

"No such status for Nero, though he did commission the Subiaco Dams. Necessary to create a series of artificial lakes beneath the infamous ruler's villa, they were the highest dams in existence until the Middle Ages. Hadrian's more public-minded white-marble temple at Cyzicus in modern-day Turkey was known as unusually splendid even by the standards of that genre of building; now only its foundations remain, with archaeological digs turning up the occasional fragment."

"In the former Constantinople, the Church of the Holy Apostles is remembered as the second-most famous vanished early Christian church, after only the old St. Peter's Basilica in Rome. Hagia Sophia may still be around, but the Column of Justinian that once stood between it and the Great Palace was melted down for scrap long ago."

Most Roman infrastructural achievements now exist primarily as ruins, with only a few bridges still functioning. Surface remains can convey the empire's scale, but numerous major constructions have vanished entirely. Trajan's Bridge spanned more than a kilometer across the Danube and was the longest bridge of its time. Nero's Subiaco Dams created artificial lakes and were the highest dams until the Middle Ages. Hadrian built a white-marble temple at Cyzicus of exceptional splendor, now reduced to foundations and fragments. In Constantinople, the Church of the Holy Apostles and other monuments like the Column of Justinian have been lost.

Read at Open Culture