A hillwalker has discovered a spectacular 120 metre glacial tunnel in Scotland.
Les Smith, 69, stumbled upon the snow tunnel in a gully on Carn na Caim in Badenoch and Strathspey, reports Scotland Now.
The snow tunnel is crafted by ice and water and features an incredibly patterned "ceiling".
Located on the east side of the Drummochter Pass, it has miraculously survived the summer due to its hidden position, reports the Daily Record.
Smith from Linlithgow, West Lothian said: "I've climbed a few Munros, but this was one of the biggest challenges of my life.
"We started off in sunshine and went through torrential rain to end up in ice and snow. But that's climbing in Scotland.
"It's reinvigorated me to climb more beyond my 70th birthday."
Neil Reid of the Mountaineering Council of Scotland, said snow tunnels were created when a stream is drifted over by snow during the winter.
"As the thaw comes, the stream runs under the snow and melts it from below," he said.
"Last winter there was especially heavy snowfall up on the mountains and drifts many metres deep were formed in some places, which have lasted well into the summer.
"The result is that some of these snow tunnels formed by streams are quite spectacular, with characteristic scalloped patterns in the walls and roof, and can even be high enough to stand up in."
Mr Reid added: "On a note of caution, covered over streams can present a danger to walkers, especially in old snow which has lasted into the summer, where the 'roof' can be very thin and prone to collapse.
"Apart from the possibility of injury in the initial fall, some streams can be steep and rocky, and the flow of water dangerously strong.
"It is possible for someone to be swept deeper into one of these tunnels, with a danger of drowning or further injury, possibly fatal."
Les avoided the potentially fragile "roof". He said: "The tunnel runs around 120 metres long by 40 metres wide down this northwest-lying gully that stays in shadow for most of the day and rarely sees the sun.
"Because of that, the snow is still several metres deep in places, but below it the stream has run through to create this spectacular tunnel.
"It's like a mini-glacier.
"I climbed down to the mouth of the tunnel. I went fully equipped, but with even better correct gear you could probably climb the whole distance from within."