CNN  — 

Over the years, the small Vermilion Heritage Museum in Alberta, Canada, tried everything in its power to unlock an old safe tucked away in its basement.

The museum hired blacksmiths, called the manufacturer, contacted former employees and challenged guests to play around with the safe – but nobody had any success.

Until last month, when a visitor to Vermilion cracked the code on his first try, much to the astonishment of everyone present.

Stephen Mills, from Fort McMurray, Alberta, was on a family camping trip with his wife, his two children and his father-in-law.