A holy well or sacred spring is a well, spring or small pool of water revered either in a Christian or pagan context, sometimes both. The water of holy wells is often thought to have healing qualities, through the numinous presence of its guardian spirit or Christian saint. They often have local legends associated with them; for example in Christian legends, the water is often said to have been made to flow by the action of a saint. Holy wells are often also places of ritual and pilgrimage, where people pray and leave votive offerings. In Celtic regions, strips of cloth are often tied to trees at holy wells, known as clootie wells. Names The term haeligewielle is in origin an Anglo-Saxon toponym attached to specific springs in the landscape; its current use has arisen through folklore scholars, antiquarians, and other writers generalising from those actual 'Holy Wells', which survived into the modern era. The term 'holy-hole' is sometimes employed. Culture and representation Holy wells in different forms occur in such a wide variety of cultures, religious environments, and historical periods that it seems to be a universal human instinct to revere water sources. However, the fragmentary nature of the evidence, and the historical differences among cultures and nations, make it very hard to generalize. While there are a few national studies of holy well lore and history, mainly concentrating on Ireland and the British Isles, there is a need for more work examining other regions. The earliest work specifically devoted to holy wells is Philip Dixon Hardy's Holy Wells of Ireland (1836), a Protestant attack on Catholic observances at Irish wells bearing the names of Christian saints, or otherwise considered sacred. By the later 19th century, the term had acquired its current usage: Robert Charles Hope's The Legendary Lore of the Holy Wells of England (1893), the first general survey of its kind, included a number of named wells which were not dedicated to saints (as well as some rivers and lakes with associated folklore, as Hope mentioned in his subtitle). Origin and development In ancient Greece and Rome, a nymphaeum or nymphaion (), was a monument consecrated to the nymphs, especially those of springs. In England, examples of reverence for wells and springs occur at a variety of historical periods. The medieval traveller William of Worcester saw a 'holy-hole, or well' within the cave at Wookey (Somerset), a