A new landmark has been added to the impressive array of buildings in Durham City thought worthy of listing by heritage officials.
But unlike the architecturally-acclaimed cathedral and castle above the River Wear, this latest attraction is a 469 feet (143 metres) tall concrete mast.
English Heritage announced on Wednesday that the 1960s concrete County Police Communication Tower at Aykley Heads in Durham had been granted Grade II listed status.
The tower was one of seven 20th Century structures listed, representing the strides made by the UK's
telecommunications industry in the 1950s and 1960s.
English Heritage has said "the elegant, ultra-thin design, for the County Police Communications Tower at Aykley Heads in Durham, responds to its aesthetically sensitive site overlooking Durham Cathedral".
The mast was built between 1965 and 1968
It continued: "Precast reinforced concrete allowed the contractors to build a slender but rigid mast demanded by the sensitive equipment to avoid distortion of the narrow radio frequencies."
The new group of listed buildings came after a survey of post-war communication buildings.
The tower was built and designed by Ove Arup and Partners between 1965 and 1968.
A Durham Police spokesman said they were "delighted" at the news.
'Slender and inconspicuous'
Arts Minister Baroness Blackstone said: "Listing is not just about trying to protect ancient buildings but also about trying to protect 20th century buildings.
"These mark the early milestones of Britain's transformation into one of the most technologically advanced nations in the world today."
The Durham Police structure was designed to be slender and inconspicuous to the environment and aesthetically sympathetic to Durham Cathedral.
It was precast on ground level in five elements thus avoiding full height scaffolding and formwork, as well as avoiding the need to make the temporary structure secure against wind effects.
The mast is superimposed on a tripod which avoids high bending movement at ground level, and not only gives a higher natural frequency, but also leads to a more elegant form.