A solo trip through Europe and Kenya when he was a young adult was "memorable" and "special," Obama said at the World Travel & Tourism Council's Global Summit 2019, and it taught him a lot about himself.
"I was already in my mid-20s. I had graduated from college, I had already worked," Obama told Hilton CEO and WTTC chairman Christopher Nassetta.
But "I'd never traveled to Europe before. That trip was memorable because it was part of my self discovery," he said.
"...I did not have any money," Obama said. "I was traveling alone. In Europe, I was in these 'pensiones' [hostels] and I'd basically buy a baguette and cheese and ate that every day, and some wine on occasion.
"I still remember taking the bus from Madrid to Barcelona, overnight. My Spanish wasn't very good. I befriended this fellow traveler on the bus who could speak English and I shared with him some bread and he shared with me some wine. And we arrived in Barcelona and it was just daybreak and I remember walking toward Las Ramblas. The sun was coming up...
"Those kind of trips are memorable because they're part of you as a young person traveling discovering what your place in the world is," he said.
Obama says he then went on to Kenya, where he stayed for a month. His father, who was Kenyan and whom he'd only met once, had passed away, so he "wanted to understand him and understand the land he was from," he said.
"I went on safari and met members of my family I hadn't met before. That was very special," he said.
Now, said Obama, traveling with his family is what makes a trip truly memorable for him.
"Traveling now with my children is now what's most important," Obama said, according to Travel + Leisure. "There is something spectacular about seeing a new place, being exposed to new ideas and experiencing a new culture. Traveling makes you grow. But as a parent, when you are able to watch that sense of discovery in your children's eyes? That is more special than anything else. "
Obama also said he sees travel as a way to unite people.
"I believe in bringing people together instead of separating them out as us and them," Obama said. "If we try to reassert hard, fixed borders at a time when technology and information are borderless, not only will be fail but will see greater conflict and clashes between peoples."
Obama plans to travel to Taj Mahal in India and Angkor Wat, a famous temple complex in Cambodia, according to Travel + Leisure. He says he is also going to explore Patagonia in South America, Antarctica and Brazil.
Like this story? Subscribe to CNBC Make It on YouTube!