Next week, on June 24, marks 50 years of the Kingsway Tunnel that runs under the River Mersey from Wallasey to Liverpool.
The Birkenhead Tunnel - also known as the Queensway Tunnel - was the first tunnel for vehicles across the Mersey after it was built in 1934 - the first tunnel was for the underground railway in 1886.
The Queensway Tunnel struggled to cope with the volume of traffic so it was agreed a second tunnel would be constructed under the authorisation of the Mersey Tunnels Act 1965.
READ MORE: Captivating images show the creation of Kingsway Tunnel
Work began in 1966 by the building firm Edmund Nuttall Limited - today known as BAM Nuttal - who had also constructed the Liver Building on the Liverpool waterfront.
On the Wirral side, the area used for the approach to the Kingsway Tunnel entrance took over the old Seacombe train line.
It took five years to complete and was officially opened on June 24, 1971 by the Queen.
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Both sides of the tunnel run for 3.7 miles and often sees upwards of 40,000 vehicles a day - pre-pandemic.
Out of the Kingsway and Queensway Tunnels, the Kingsway is the only one suitable for heavy good vehicles.
Memory Lane Widget
As part of the celebrations for its 50th anniversary, the ECHO was invited to join tunnel staff as they carried out maintenance work.
'You can purchase a copy here of the 64 page special packed with nostalgic photos and articles from your local area'.
During the visit, we were able to see part of the tunnel never seen by the public and a close-up look at an eerie empty space that is usually filled with cars.
You can see some of the incredible hatches leading to special maintenance tunnels and parts of the structure only a handful of people have ever seen.