In this episode, Ben journeys from Stroma, inhabited 1,000 years ago and owned by the same family for generations, to Swona, its first inhabitants being the Vikings and later a multi-generational family who shared their island with a feral herd of cattle, and then to the towering prehistoric cliffs of St Kilda, the most remote of Scotland's Lost Worlds. Stroma: Ben has been travelling to the Scottish Islands since he was six and always glimpsed the island of Stroma from John O'Groats, the most northerly point of mainland Britain. A beautiful island with idyllic looking cottages, Ben now finally gets to travel there to meet its owner William Simpson, a farmer who has kept sheep on the island for the past few decades and inherited the island from generations before him. Stroma's name is from the Old Norse language and translates as ‘island in the stream', a reflection of the fierce tides that affect this entire area. It was first inhabited around 1,000 years ago, but since its complete abandonment in 1997, it's been slowly disintegrating into the ground. Ben discovers that in 1958 the island was even offered as a prize on an American TV quiz show. Swona: Ben spends time with three generations of the Annal family, who work hard to restore the island's crumbling buildings and preserve their ancestors' legacy. People have lived on Swona since 500BC, with the Vikings among the first to settle there. By the mid-18th century, the island sustained a healthy population of nine families, most of whom earned a living from fishing. In the 1920s, the collapse of the fish market made it harder for Swona's community to survive, and its final two residents left for good in 1974. St Kilda: The most famous Scottish Lost World of them all, despite its remote location, is thought to have been home to people for 4,000 years. At its peak, St Kilda's population approached a 200-strong community who carved out a life in this remote, inhospitable environment. Ben spends the night camping on the island, meets archaeologist Clare Henderson, marine ranger Craig Nesbit (to discuss the estimated 210 different species of sea birds that live here) and spends time with John MacDonald, whose parents are buried on the island and who has created a living museum to show what life was once like here.