Good morning. I'm Renee Montagne. In 2009, a young British man began a quest to visit every country in the world. To make it interesting, he set out to do it without flying - something never done before. This week, after nearly four years of traveling by train, taxi, bus and boat, Graham Hughes accomplished that feat. He filled four passports, trekking through every nation and disputed state, ending in south Sudan - a country that didn't exist when he started out. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.