Which twin rail tunnels opened in 1910 to bring Pennsylvania Railroad trains into Manhattan?

The twin tunnels that opened in 1910 to carry Pennsylvania Railroad trains into Manhattan were the North River Tunnels. They run beneath the Hudson River between North Bergen, New Jersey, and Pennsylvania Station in Manhattan.

The Pennsylvania Railroad built the tunnels as part of its New York Tunnel Extension, a huge project that also included Penn Station, approaches across New Jersey, and the Portal Bridge over the Hackensack River. Before the project, PRR trains terminated at Exchange Place in Jersey City, forcing passengers to continue by ferry or elevated railway.

The tunnels opened on November 27, 1910, when service to the new Pennsylvania Station began. Each tube carries a single track, creating a pair of parallel rail tunnels. Their opening gave the Pennsylvania Railroad direct access to Manhattan from the west and transformed regional rail travel.

A common mix-up is the East River Tunnels. Those are four separate tubes east of Penn Station, linking Manhattan with Queens and Sunnyside Yard. The Hudson-crossing pair is specifically called the North River Tunnels.