Which road tunnel under the River Mersey links Liverpool and Birkenhead?

The Queensway Tunnel is a road tunnel under the River Mersey, in the north west of England, between Liverpool and Birkenhead. Locally, it is often referred to as the Birkenhead Tunnel or Old Tunnel, to distinguish it from the newer Kingsway Tunnel (1971), which serves Wallasey and the M53 motorway traffic.

The tunnel entrances, toll booths and ventilation building exteriors were designed by architect Herbert James Rowse, who is frequently but incorrectly credited with the whole civil engineering project. Their decoration is by Edmund Thompson. These are Grade II listed buildings. More than 1.2 million tons of rock, gravel, and clay were excavated; some of it was used to build Otterspool Promenade. Of the 1,700 men who worked on the tunnel during the nine years of its construction, 17 were killed.

At the time of its opening it was the longest road tunnel in the world, a title it held for 14 years until the opening of the Vielha Tunnel in Catalonia, Spain in 1948, though it remained the longest underwater tunnel as of 1955. The tunnel, which cost a total of £8 million, was opened on 18 July 1934 by King George V; the opening ceremony was watched by 200,000 people.