Ireland doesn't take up much room on the map, but few places have an identity so celebrated across the world. Hannah Fry journeys to her ancestral homeland to discover what it means to be Irish. She traces her Irish DNA, rides the waves of a surf boom, explores connections to the land at the races and reveals hidden depths in the Irish language.

Hannah Fry visits Iceland to uncover the secrets behind its success. She meets scientists predicting lava flows, sees how geothermal power fuels an algae farm, explores Icelandic DNA and rides horseback through ancient Viking landscapes - all to reveal how a tiny, isolated island, shaped by geological extremes, is thriving against the odds.