Otisville Tunnel

It is the longest tunnel in the Metro-North system, at 5,314 feet (1,620 m) in length.

[1] Although the track curves at the western opening, the tunnel itself is a straight line, allowing an observer to see all the way through.

[2] The tunnel was built in 1908 by the Erie Railroad at the highest point of the Graham Line.

The original Erie mainline went over the hill and connected at both ends with the tunnel.

Later the "over the hill" tracks were abandoned and all trains ran through the tunnel.