Most of us learn from an early age that islands do not sit atop the world’s oceans, drifting as they see fit, but are rather harnessed to the seafloor in the same way countries and continents are.

Most of them, anyway.

This week a timelapse clip emerged of two small islets moving across a lake in Norway and it piqued our curiosity. How do islands float? Where are they, who knows about them and are they real?

It is not clear where exactly the islands seen here are, though one commenter on Reddit clearly knew, explaining that it is possible to walk on them though “they’re not incredibly sturdy… and depending on the size, might flip”.

Perhaps more interesting are the islands beyond lakes, in the...