Richard Lyon, who has been diagnosed with prostate cancer, has been climbing Munros and Corbetts every day since April and performing a newly composed tune to mark each achievement.
His Fiddling the Munros challenge is raising funds for Friends of the Beatson and Prostate Cancer UK.
Mr Lyon, from Ayrshire, is on the final stretch and is due to finish at Ben Klibreck on Wednesday after scaling Ben Hope and Ben Loyal. He has walked, cycled and sailed about 745 miles during the challenge.
Before setting off he had said he was "determined to make the most of life".