Chalice Well rises from the earth at the base of Glastonbury Tor, the conical hill that dominates the Somerset landscape and has been a sacred site since the Bronze Age, more than three thousand years ago. The well is a natural chalybeate spring, meaning its water is rich in iron salts that oxidise when they meet the air, turning the water a deep reddish-brown and leaving ochre deposits on every stone it touches. The spring flows at a constant rate of approximately twenty-five thousand imperial gallons per day, and even in the driest summers, when every other well in the region has failed, the red water continues to pour from the lion's head spout and fill the shallow pool below. Archaeological evidence, including flints from the upper Paleolithic and Mesolithic periods, Iron Age pottery, and Roman and medieval sherds found nearby, confirms that the well has been in almost constant use for at least two thousand years, making it one of the oldest continuously flowing sacred springs in Britain.

The Christian legend of the well begins with Joseph of Arimathea, the wealthy follower of Christ who, the Gospels tell us, took the body of Jesus from the cross and laid it in his own tomb. In medieval Arthurian romance, Joseph became the keeper of the Holy Grail, the cup used by Christ at the Last Supper and later employed to catch the blood of the crucifixion. The twelfth-century French poet Robert de Boron wrote that Joseph received the Grail from an apparition of Jesus and sent it with his followers to Britain. Later legends, elaborated at Glastonbury Abbey, claimed that Joseph himself travelled to the Isle of Avalon, landed on Wearyall Hill, and thrust his staff into the ground, where it took root and became the Holy Thorn tree that blossoms every Christmas. The same legends declared that Joseph buried the Holy Grail beneath the Tor, at the very spot where the Chalice Well now flows, and that the waters turned red the moment the sacred vessel touched the earth. The colour was said to represent either the blood of Christ or the rusty iron nails that pierced his hands and feet on the cross.

The well acquired its name and its Christian mythology in the Middle Ages, but its sacred character predates every church. The Celts who lived in the Somerset landscape before the Romans arrived would have recognised the spring as a threshold to the Otherworld, a place where the waters of the underworld rose to meet the light of the living. In the landscape mythology of modern Glastonbury, Chalice Hill is seen as the pregnant belly of a great goddess whose body is mapped across the entire vale: the Tor is her left breast, Wearyall Hill her thigh, and the abbey ruins lie in the most potent and creative part of her form. The red spring and its twin, the White Spring that flows with calcium-rich water only metres away, represent the two currents of life: the blood of the womb and the milk of nourishment. This goddess reading of the landscape is not medieval but ancient, rooted in the pre-Christian veneration of springs as the dwelling places of female deities whose waters could heal, curse, and prophesy.

The well cover that stands over the spring today was designed by Frederick Bligh Bond, an architect and archaeologist who excavated Glastonbury Abbey in the early twentieth century and claimed to receive instructions from the spirits of dead monks. The cover is a circular wooden block framed in wrought iron, and its central motif is the Vesica Piscis, two interlocking circles that create an almond-shaped mandorla in the centre, an ancient symbol of the divine feminine and the sacred union of opposites. A sword pierces the symbol vertically, a reference to King Arthur and the line of sacred kingship that runs through the Arthurian landscape. The water flows from a carved lion's head into a five-sided chamber, then passes underground to the Healing Pool, where visitors may paddle in the mineral-rich warmth. From there it flows through the gardens in a channel shaped like the Vesica Piscis, a geometric form that echoes the well cover and unites the architecture with the sacred geometry of the site.

The Chalice Well Trust was founded in 1958 by Wellesley Tudor Pole, a spiritualist and mystic who believed the well was a centre of world peace and healing. The trust maintains the gardens as a sanctuary open to all faiths and none, and the well has become a place of pilgrimage for Christians seeking the Grail, pagans honouring the goddess, and spiritual seekers of every kind. The water is still believed to possess healing properties, a belief that can be traced back to the sixteenth century and that was revived in the eighteenth century when a tourism campaign claimed the Chalice Well water could cure ailments. In recent years the water has been found to be naturally radioactive, a property that adds to its mystique without diminishing its flow. The well is now a Grade I listed building, protected by law as a structure of exceptional interest, and the gardens receive thousands of visitors every year who come to drink from the lion's head, to sit in silence beside the red pool, and to touch the stones that have been wet with sacred water for two thousand years.