Hikers bumped into Mel Gibson on the top of a mountain in Ireland

The actor-director is currently filming biopic The Professor and the Madman

One of the last people you'd expect to see atop an Irish mountain is Mel Gibson - but that's exactly who three teens found when they reached the summit.

Heather Fogarty, Michael O'Connor and Shane Gallagher had hiked up Sugarloaf Mountain in County Wicklow last Sunday (9 October) when they casually bumped into the actor-director who, the Derry Journal reports, was more than happy to pose for a photograph with them.

Fogarty expressed her excitement about meeting the Oscar-winner on Instagram.

“Climbed the Sugar Loaf today,” she wrote. “It was great fun bit of yoga thrown in and to top it all off we met Mel Gibson at the summit! #SolidSunday.”

Gibson (Mad Max, Lethal Weapon) was having a day off from filming The Professor and the Madman which he's starring in alongside Sean Penn and Game of Thrones actor Natalie Dormer. Gibson acquired the film rights to the novel shortly after winning an Oscar for Braveheart in 1995.

The bestseller from author Simon Winchester - originally published in England as The Surgeon of Crowthorne in 1998 - tells the story of Professor James Murray, the talented linguist who compiled the Oxford English Dictionary in 1857.

His next film will be Hacksaw Ridge which stars Andrew Garfield as conscientious objector Desmond T. Doss.