Crick, Monmouthshire an important junction on the Roman road sometimes known as the "Via Julia" which ran from Bath ("Aquae Sulis") across the Severn estuary to Sudbrook and on to Caerwent ("Venta Silurum") and Caerleon ("Isca Augusta"), now in Wales. At Crick the route met the roads to Gloucester ("Glevum") and Monmouth ("Blestium"). There is also evidence of an early Norman motte and bailey castle at Ballan Moor near Crick, probably built by the Ballon family in the late 11th or early 12th century. In July 1645, during the English Civil War, a mediaeval hall at Crick was the site of a
Aphanizomenon flos-aquae toxic chemicals released when cells die. Once released (lysed), and ingested, these toxins can damage liver and nerve tissues in mammals. In areas where water quality is not closely monitored, the World Health Organization has assessed toxic algae as a health risk, citing the production of anatoxin-a, saxitoxins, and cylindrospermopsin. Dogs have been reported to have become ill or have fatal reactions after swimming in rivers and lakes containing toxic "A. flos-aquae". Microcystin toxin has been found in all 16 samples of "A. flos-aquae" products sold as food supplements in Germany and Switzerland, originating from Lake Klamath: 10 of 16