The search reaches its climax as Steve Backshall has a very close encounter.
Nicholas Crane looks at how Timothy Pont set off to survey Scotland in 1583.
A look at mountains, from their origins at earth's lowest places to the summit of Everest.
Film which explores the extraordinary ways in which people survive at extreme altitudes.
A portrait of the beauty and surprising wildlife of Scotland's Cairngorms National Park.
A history of one of the world's most challenging mountains and its infamous north face.