Neil Oliver goes on a journey to reveal the sacred face of Britain, an ancient landscape of belief and ritual that still lies hidden just below the surface of the modern world. In the first episode, Neil is in search of the very first stirrings of religion in Britain. In the south of England and on the Scottish borders great tombs are evidence of ancestor worship among the first farmers of the Neolithic and an extraordinary discovery in Herefordshire reveals what really lies beneath their burial mounds. In the flint mines of Grimes Graves in Norfolk, he discovers how stone age miners carried their religion deep underground.

Neil Oliver goes in search of Bronze and Iron Age sites that were sacred to ancient Britons, with water seen not just as a source of life, but also of reverence. At Flag Fen near Peterborough he discovers a vast ancient causeway built across the fens, with sacred objects placed among its timbers. Neil travels to Anglesey, where swords, precious artefacts and even a slave chain were ritually deposited. Moving on to Bath and its sacred spring, Neil discovers an early version of the habit of throwing coins into water. Once here the Romans recognised the old gods but also brought their own too, making Bath one of the most sacred sites in Roman Britain.

Neil Oliver examines how the creation of saints by the early church led to a new generation of Sacred Wonders across Britain. On Iona, in the Inner Hebrides, Neil discovers the traditional resting place of Macbeth. He also delves back through time to discover how St Columba sanctified the island with a tough brand of monasticism all the way from the Egyptian desert. On Lindisfarne, Neil sees how the epic journey of St Cuthbert led to the writing of the extraordinary Lindisfarne Gospels and the building of Durham Cathedral. At Canterbury Cathedral, Neil learns how St Thomas Becket's grisly murder was harnessed to build its nave, one of the great glories of medieval architecture, and on Glastonbury Tor in Somerset, he investigates layer after layer of powerful legend in the story of the Holy Grail, the sacred cup of everlasting life.