To some they are nostalgic reminders of an age of clean lines, progress and hope for the future.
For others they are unsightly concrete carbuncles whose absence would not be missed.
But the heritage campaign group which tried to save the old Central Library has now turned its attention to the last few Brutalist icons in Birmingham and revealed a watchlist of those it fears could be lost for ever.
The Brutiful Birmingham Action Group has revealed the sites which could easily fall prey to bulldozers and redevelopers, destroying the last vestiges of the city's 1960s architectural heritage.
Although it lost its battle to save architect John Madin's famous old library from demolition, it hopes it can work with developers and the planning industry to influence future projects.
The move follows the controversy over the Ringway Centre - the sweeping, curved 1960s building which spans the length of Smallbrook Queensway in the city centre.
Commercial Estates Group plans to bulldoze the section from Holloway Circus to Hurst Street and replace it with a 22-storey residential tower.
It will then strip back, reclad in glass and renovate the remaining section up to the Bullring.
Campaigners suffered a blow last week when Historic England recommended to the Government that the Ringway Centre be granted immunity from listing.
Watch: See bird's eye view of demolition of Central Library
If approved, it would pave the way for its partial demolition as the ruling would prevent the building from being granted listed status for five years.
Mary Keating, from Brutiful Birmingham Action Group, told the Post: "We are campaigning to save the best of what Birmingham has left of its 20th century architecture, much of the very best having already been destroyed.
"We are currently anxious about what may happen next with Smallbrook Queensway but believe that listing a building is not necessarily the only way to save its integrity.
"We are looking to find ways in which we can work more co-operatively with developers to achieve improved economic viability at the same time as maintaining the essence of the building and the best architectural features.
"The watch list is intended to be flexible and responsive and will change as circumstances dictate."
The group's name is a nod to the divisive Brutalist movement of architecture prevalent during the 1950s, 60s and 70s which featured so prominently in Birmingham, particularly through the legacy of Mr Madin.
Among the other buildings on the Brutiful Birmingham watch list are Madin's Chamber of Commerce House, in Edgbaston - itself granted immunity from listing earlier this year - Quayside Tower in Broad Street and Martineau Galleries in the city centre.
The latter has been the subject of numerous plans to regenerate the site and was bought in 2015 by Hammerson, the company which co-owns both the Bullring and Grand Central shopping centres.
Ms Keating added: "We have a wide and loyal following on our Facebook page and the demographic is younger than would be found in other similar organisations.
"Attracting business and young professionals to the city is one of the commercial sector's aims.
"As part of this, 20th century architecture and mid-century design support a city that strives to be recognised as a sophisticated and international location.
"Part of our mission is to educate and raise the profile of this heritage in Birmingham."
Birmingham's Brutalist classics
➤ Ringway Centre, Smallbrook Queensway - designed by Rotunda architect James Roberts as part of the Inner Ring Road scheme. Completed in 1962. The innovative structure of the building was constructed in-situ of pre-cast concrete.
➤ Quayside Tower, Broad Street - designed by John Madin and completed in 1965. It was refurbished in 2003 but retains original modernist reliefs above its main entrance.
➤ Birmingham Chamber of Commerce House, Harborne Road, Edgbaston - designed by John Madin. Completed in 1960. Houses John Piper's abstract mosaic. Calls have been made to list the mural separately.
➤ Martineau Galleries, off Corporation Street - designed by Sir Frederick Gibberd and opened in 1966.
➤ Hockley Circus, under Hockley flyover - features artwork called Climbing Wall, by William Mitchell, constructed in 1968.
