After 3/4 mile is the only tunnel on the canal, at Brandwood.

Near Blankenheim it passes through the only tunnel on the route.

To the east is the only tunnel on the line, connecting to the valley of the Zorge.

It is also the only tunnel where tolls are charged.

It was the only tunnel that wasn't sealed off by a blast door.

The only tunnel was bypassed by a cutting in 1840.

It is also the only tunnel on Interstate 71.

It is the only tunnel on a limited-access highway in the state of Connecticut.

Khannouchi took off from the two after coming out of the only tunnel of the race.

This was the only tunnel on that railway, which ran for the most part over the Fens.