Here be dragons and wergs (for Aril)

Nykerpole : here be dragons
Nykerpole is a very obscure well. Indeed, it is now not a well at all, but a mediaeval place-name, recorded first in 1272, indicating a well now lost, at Mildenhall near Marlborough. Nevertheless, I include Nykerpole here because, like Puckwell, the place-name recalls a legendary well-dwelling creature.
Mildenhall (pronounced Mine-all) was Roman Cunetio. Two Roman shaft-wells have been found in the area, one of which contained a Saxon burial, the remains of a female skeleton with a knife, pins, buckles and beads. Black Field is the site of the Roman settlement, and Roman ghosts have been seen here (Wiltshire 1984, pp. 25-6). Nickamoor Field lies just west of Black Field beside the River Kennet. A placename of the sixteenth century, Nicapooles Croft, may refer to this very field, or to another associated with it. Centuries have passed, and we will probably never know the exact location of Nykerpole, the nicor-pool of Anglo-Saxon times which gave its name to Nicapooles Croft and Nickamoor Field (Gover 1939, p. 499). The nicor was a great water-dwelling monster of the dragonish or sea-serpent type: two nicras are described in Beowulf, the Anglo-Saxon epic poem of the early eighth century. Nowadays the nicor lingers most notably in the Knucker Holes of Sussex, great deep pools of water in whose bottomless depths lurked the Knucker itself (Simpson 1973, pp. 37-42). But it is clear that, centuries ago, Wiltshire too had its Knucker which perhaps, like its Sussex cousins, would come crawling up out of its pool to terrorise the people of the gentle Kennet valley.
Location: Nicamoor Field is at SU 214 694, Sheet 1186. Footpaths run either side of the River Kennet. 
http://people.bath.ac.uk/liskmj/living-spring/sourcearchive/ns6/ns6kmj1.htm

The strangely named hamlet of Werg was a community of nine dwellings on the River Kennet."One of the many pools on the river, as it wove its way through the water meadows was "Nicker Pool", where it is said the water spirits played. When the climatic conditions are right, the whirling wraiths can still be seen, so that the local name had good cause to be established."

Werg of course is a word that can be transformed into many meanings but given that there were only nine dwellings by this stretch of the river near Mildenhall, one of the meanings is outlaw or criminal, and presumably popular medieval myth has taken up the word and transformed a particular happening of the water spiralling around maybe, a bit like cropcircles, and transformed it into water wraiths, probably the spirits of the poor wretches who lived here.

Taken from this blog which goes back to 2008.  Also the river Cunetio (and yes it is a Celtic name Romanised) or Kennet as it is now called has an interesting past.