A mountain rescue team member believes he has become the first British person to have climbed the highest peaks in the Arctic and Antarctic.
Bob Kerr, 33, from Melvich, in Sutherland, reached the summit of Mount Vinson in Antarctica on Christmas Day.
The Assynt Mountain Rescue Team member climbed Gunnbjørn Fjeld in Greenland in June 2004.
Mr Kerr has now climbed the highest mountain on six of the seven continents.
He is hoping to tackle Mount Everest at a later date.
The mountaineer hopes to confirm his potential claim to being the first British person to have reached the tops of both 4,892m (16,050ft) Mount Vinson and 3,694m (12,119ft) Gunnbjørn Fjeld.
Mr Kerr also made first ascents of two previously unclimbed mountains, during the Greenland expedition.
He said: "I joined a small international team of mountaineers for the attempt on Mount Vinson.
"The ascent of the mountain was a team effort and all successfully reached the summit due to good co-operation and teamwork.
"The Christmas 2011 Mount Vinson expedition was successful, without incident, and has made me potentially the first British person to have ever ascended the highest point in both the Arctic and the Antarctic."
Englishman Chris Mothersdale, Senan Foley, from Ireland, and American Ryan Laughna were the others in Mr Kerr's team.
To reach the foot of Mount Vinson involved a series of plane trips.
From Punta Arenas at the southern tip of Chile, they flew in a chartered Kazakhstan Illyushion 76 cargo plane to the Union Glacier on Antarctica.
After camping briefly on the glacier, they were then flown by a small aircraft to a snow-covered glacier near the mountain.
The team acclimatised themselves in preparation for Mount Vinson's high altitudes.
On Christmas Eve, US teenager Jordan Romero reached the summit to become the youngest person to have climbed all the seven highest mountains.
Mr Kerr and his companions were able to congratulate the 15-year-old in person when he returned to Vinson's high camp.
The Assynt MRT member and his team made their ascent on Christmas Day morning in freezing temperatures and high winds.
Mr Kerr said: "After six and a half hours of effort the team safely reached the summit of Mount Vinson.
"The wind speed had dropped to about 30 knots and the temperature was below -25C on the summit when the team arrived, which meant that the resultant wind chill was of the order of -55C to -60C.
"Cameras had to be taken out from under multiple layers of clothing and the outer pairs of gloves removed so that a summit photo could be taken.
"Taking photos in these conditions is very risky as the extreme cold can lead to the development of frostbite within minutes."
The team successfully returned to the high camp and later base camp.