The Liberty Tunnels are a pair of tunnel

Tunnel

A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...

s located in Pittsburgh, Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

 that allow motorists to travel between the South Hills of Pittsburgh

South Hills (Pennsylvania)

The South Hills is a term generally used to collectively describe the southern suburbs of Pittsburgh, Pennsylvania, and the neighborhoods in the City of Pittsburgh south of the South Side Slopes. The city neighborhoods include Knoxville, Mt. Oliver, Allentown, Banksville, Beechview, Brookline,...

 and the city, through Mt. Washington

Mount Washington (Pittsburgh)

Mount Washington is a neighborhood in Pittsburgh, Pennsylvania's south city area. It has a zip code of 15211 and has representation on Pittsburgh City Council by both the council members for District 3 and District 2 .It is known for its steep hill overlooking the Pittsburgh skyline, which was...

. The tunnels were vital in the expansion of the South Hills suburbs by providing a direct route to the city, eliminating the time-consuming task of navigating around or over Mt. Washington and its inclines.
The tunnels were designed by Amos D. Neeld, who would also supervise the construction of the adjoining Liberty Bridge

Liberty Bridge (Pittsburgh)

The Liberty Bridge, completed in 1928, connects downtown Pittsburgh, Pennsylvania to the Liberty Tunnels and the South Hills neighborhoods beyond...

, which gives travelers a way to cross the Monongahela River

Monongahela River

The Monongahela River is a river on the Allegheny Plateau in north-central West Virginia and southwestern Pennsylvania in the United States...

 after passing through the tunnels.