Grade-II listed status has been awarded to nine rare telephone boxes in and around Hull.
The city's cream-coloured K8 kiosks are among 50 remaining out of 11,000 placed around the UK between 1968 and 1983.
Hull's telecoms network was not operated by British Telecom which meant the boxes remained in place after the company was privatised in 1984.
Hull is the only place in England where the local council ran the public telephone network, which is now run by an independent company.
The K8 was designed in 1965-66 by architect Bruce Martin who was commissioned by the General Post Office, owners of the public telephone network at the time.
In contrast to the intricate glass panelling of Giles Gilbert Scott's iconic K2 and K6 boxes, the K8 was notable for its modern and minimalist appearance, making it simpler to repair and maintain.
Historic England's Sarah Charlesworth said the booths were ‘a beloved part of England's heritage’.
‘For many of us they've been the scene of memorable moments in our own lives from furtive conversations with first boyfriends to desperate calls home when we've been in a fix.’
Catherine Croft of the Twentieth Century Society added: ‘They're the perfect example of how good design, no matter how small, can help enrich our high streets and communities.’
