Police in the Lake District said they are concerned for a walker who was last seen in Wasdale Head.
Dawid Kancyr, 28, went missing on Saturday, Cumbria Police said.
Wasdale Head is the starting point for routes up several Lakeland mountains, including Scafell Pike and Great Gable. Police said mountain rescue teams have been searching for the walker.
He is described as white, 6ft 3ins (1.91m) tall, of medium build with a brown beard and brown hair. He was last seen wearing a black t-shirt, grey trousers and brown boots. He also has a grey hoody and a black waterproof jacket which he may be wearing.
Cumbria Constabulary is appealing for anyone with information to get in touch by calling 101 quoting log number 11 of 15 October.