Euphrates Tunnel

The Euphrates Tunnel was allegedly a 929 meter long tunnel built to connect the two halves of the city of Babylon; archaeologists believe it was built between 2180 and 2160 BCE. Construction began with a temporary dam across the Euphrates river, and proceeded using a "cut and cover" technique. The tunnel was supposedly lined with brick and waterproofed with asphalt. No other sub-aqueous pedestrian tunnel was attempted until Marc Brunel built the Thames Tunnel beginning in 1824 CE. A description of the tunnel as being built and used by Queen Semiramis is given by Diodorus (fl. 50 BCE) in the Bibliotheca Historica.Philostratus (d. 250 CE) also describes the tunnel's construction in the Life of Apollonius of Tyana.

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