Greg Denning: Slow overland travel with six kids

Whenever people tell me they can't (or don't know how to) live their Nomadtopia because they have kids, I tell them about Greg and Rachel Denning, who are slowly traveling overland from Alaska to Argentina (and beyond) with their six children, world-schooling as they go. Greg joined me from their current base in Costa Rica to talk about his family's adventures learning, exploring, playing, and making a positive difference in the world.