The Hall of Memory war memorial in Birmingham city centre has been granted Grade I listed status by English Heritage.
It is one of six memorials to have their listed status upgraded by the Government, on the advice of English Heritage, to mark Armistice Day.
In 1920, a design competition among the city's architects for a war memorial was won by SN Cooke and W Norman Twist and the overall cost of £60,000 was raised entirely by public donations.
Visitors to the site in Centenary Square enter through two vast bronze doors and are met with a glass and bronze casket made by the Birmingham Guild containing two books: the First World War and Second World War Rolls of Honour.
The foundation stone was laid on June 12, 1923 by the Prince of Wales, and the hall was opened by Prince Arthur of Connaught on July 4, 1925.
Around 150,000 men and women from Birmingham served during the First World War with 35,000 coming home injured while a further 12,320 were killed.
The Grade I listing is the highest rank recognised by English Heritage and places Hall of Memory among the 2.5 per cent of buildings and structures at this grade.
It joins other notable Birmingham landmarks including Aston Hall, Curzon Street Station, St Paul's Church and New Hall.
Ed Vaizey, Minister for Heritage, said: "War memorials are the most visible reminder for all of us today of the heroism and sacrifice of service men and women through the years.
"Solemn yet reassuring, enduring but also forever of the time they commemorate, they are essential parts of our built heritage.
"So it is absolutely right that English Heritage is working to help protect and preserve them for generations to come."
The five other upgraded memorials are: Guards Memorial in Westminster, Response War Memorial in Newcastle and Port Sunlight War Memorial in the Wirral (all Grade I) and Lewes War Memorial and War Memorial in Norwich (Grade II*).