The Brecon Beacons has "lost" a mountain – after a surveyor using the latest satellite equipment found it wasn’t as big as previously thought.

Fan y Big to the east of Pen Y Fan in the national park has been reclassified as a hill.

Experienced mountain surveyor Myrddyn Phillips from Welshpool found the "drop" from the top of Fan y Big was only 28.5m (93.4ft), which means it falls below the 30m requirement to be a mountain.

Mountains have to be at least 2,000ft (610m) high with a minimum drop of 30 metres.

Although the Fan y Big stands proudly at 717.6m (2,351ft), the drop – how far the land falls from the hill/mountain’s peak before it rises again – is all important if it is to be classified as a mountain.

Neighbouring Pen Y Fan, which stands 886m (2,907ft) above sea level, is the highest mountain in the Brecon Beacons range.

Fifty-seven-year-old Myrddyn was using the latest handheld "geoexplorer" satellite device, which is accurate to within four inches (0.1m).

As a result of his findings Fan y Big has been struck off the list of Hewitts – hills in England, Wales and Ireland over 2,000ft (610m) high with a drop of 98.4ft (30m).

The episode has echoes of the 1995 film ’The Englishman who Went up a Hill but Came down a Mountain’ starring Hugh Grant, except of course Myrddyn is a Welshman.

In the movie, which won its section at the Cannes Film Festival, Grant plays an English cartographer who upsets the villagers of Taff’s Well when he concludes that the nearby mountain is only a hill.

The villagers conspire to delay the cartographer and his colleague’s departure long enough for them to build a mound at the top of the hill to preserve its mountain status.

The Brecon Beacons National Park Authority has bowed to modern technology and accepted that it has now "lost a Beacon" although it would remain a mountain in spirit.

A spokesperson said: "It is with great sadness and a heavy heart that we must announce, that through the emergence of new technological data, we have lost one of our Beacons. Perhaps, sticking to Welsh Folklore and Myth, which we are accustomed to in the Brecon Beacons, it would be more apt to state that one of our mountains has turned into a hill.

"Fan y Big, part of the high ridge heading easterly from our famous Pen y Fan has lost its status as a mountain after new data revealed that it didn’t actually meet the strict criteria.

"Although, on paper we may have lost a Beacon, we all know at Brecon Beacons National Park that Fan y Big will continue to be a mountain to be climbed, a peak to be reached and a summit worth seeing. Let the satellites and figures show what they may, but underneath the starry night sky, the Fan y Big Beacon will continue to be a pinnacle at Wales’ Best Destination."