He set out to walk around the world. After 27 years, his quest is nearly over.

Karl Bushby made a barroom bet that he could walk from the southern tip of South America all the way home to England. His friends had little faith.

“Suddenly, it became a challenge,” Bushby said of the bet he made in his 20s. “That conversation gathered steam, until eventually I did the math and thought, ‘this is doable’…I became semi-obsessed with what it would take to achieve something like this.”