Dark & controversialWeird & curious
Hennepin Island tunnel
The Eastman tunnel, also called the Hennepin Island tunnel, was a 2,000-foot-long (600 m) underground passage in Saint Anthony, Minnesota (now Minneapolis), dug beneath the Mississippi River riverbed between 1868 and 1869 to create a tailrace so water-powered business could be located upstream of Saint Anthony Falls on Nicollet Island. The tunnel ran downstream from Nicollet Island, beneath Hennepin Island, and exited below Saint Anthony Falls.
During construction of the tunnel on October 5, 1869, the river broke through the thin layer of limestone separating the river's bed from the tunnel.
Source: Wikipedia / Wikidata
Nearby
Here Before Us