Britain's highest mountain is taller than previously thought and has "grown" by a metre in the last 65 years, experts have discovered.
Ben Nevis stands at 1,345m rather than the previously recorded height of 1,344m, a new Ordnance Survey (OS) calculation found.
The change, which will be displayed on all new OS maps, is not down to a geological movement but is simply due to improvements in technology that allow a more accurate reading than when the mountain was last surveyed in 1949.
The new measurement was made by positioning a survey grade GPS receiver at the summit of Ben Nevis for two hours. Data was constantly fed to satellites and then checked by OS experts before being confirmed.
In 1949, it took a team of seven surveyors 20 nights to obtain their calculation, OS said.
The new height is exactly 1,344.527m but is rounded up to 1,345m officially.
Mark Greaves, OS geodetic consultant, was the first person to discover the change.
OS holds around 460 million geographic features in its database of the UK and regularly updates maps, with more than 10,000 changes possible each day.
OS marketing director Nick Giles said: "In reclassifying the height of Ben Nevis our map becomes even more precise.
"Now it's officially taller, I wonder how many will feel tempted to revisit its summit?"