Some bucket-list destinations are a hard sell for the whole family: too far to walk, too fragile to touch, or simply too grown-up to hold a child’s attention. Iceland’s South Coast is the glorious opposite. In a single, jaw-dropping stretch of road, you can walk behind a thundering waterfall, run across a jet-black beach, and stand at the very edge of a glacier. And every one of those moments lands just as hard for a wide-eyed seven-year-old as it does for their parents. It is one of the most family-friendly bucket-list adventures on the planet, a real-life road trip of wonders that turns a simple day out into memories your kids will talk about for years. The South…