The story of the island of Ireland's epic geological journey, spanning 1.8 billion years. Presented by Liz Bonnin.

Chapter 1: Land
We reveal how two ancient continents swallowed an ocean as they slowly approached each other over millions of years. The collision point would eventually become Ireland, and we show how the battle scar from this immense fusion runs like a suture in the rock from the Shannon Estuary in County Limerick to Clogherhead in County Louth. This merging and folding of lands took millions of years, and, even after this ancient coming together, the island's story had only just begun. As the rocks continued to move very slowly north, we explore how changing sea levels submerged Ireland in shallow tropical waters, creating the limestone deposits that dominate our landscape and are exposed so impressively at The Burren in County Clare.

We examine evidence for Ireland's long-lost deserts that formed as the island crossed the equator past present-day Egypt. In Newfoundland, the rocks reveal the legacy of the colossal forces that slowly ripped Ireland from North America over millions of years, and, on the Antrim coast, we investigate the volcanic hotspots that created the iconic Giant's Causeway around 60 million years ago.

Chapter 2: Water
With the rocks that make up the island of Ireland now in place, this is the story of the island's intricate and intimate relationship with water and ice.

At Killary Fjord, the immense bulldozing power of the glaciers which eroded and shaped the island through millenia-long cycles of formidable ice ages can be seen. In Norway, there's a look back through a window in time to see how ice continues to carve and mould the landscape.

From Croagh Patrick, there's a spectacular view of the ice-sculpted drumlins of Clew Bay, plus the intriguing 'raised beaches' in Donegal which reveal clues of ancient shorelines where the ice retreated into the sea. In Dublin Bay, there's a look at how sea levels were once so low that it may have been possible to walk to Wales.

Millions of years of geological processes have provided ideal conditions for huge quantities of water to move beneath our feet – from the unexpected source of the River Shannon to the water gently seeping through the limestone to form the stunning Marble Arch Caves in County Fermanagh. This flow and interconnection of water is central to our historical and cultural identity, and so there's a look at the 'vanishing lakes', or turloughs, that are almost unique to Ireland as a direct consequence of the island's geology and climactic conditions.

Ireland's marine territory is ten times larger than the land, so there's an expedition offshore to see how the latest seabed mapping technology offers fascinating insight into the processes that forged the island over millions of years. Plus the shipwrecks that reveal our rich maritime lore, and just beyond the far edge of Ireland's territorial waters, a look at the black smokers that offer fascinating clues to the origins of life.

Chapter 3: Life
Everything we know about life comes from the rocks, and the island of Ireland is a treasure trove of ancient life. We meet the fossil experts and dinosaur hunters uncovering the secrets of our past, and in County Kerry, we reveal the world's most reliable evidence of the first creature ever to emerge from the sea onto the land, still visible in the world-famous tetrapod tracks of Valentia Island.