Thunderfield Castle, Horley, Surrey
Photographs of this site, a moat around a flat island probably dating back to Anglo-Saxon times. It is overgrown with trees and only accessible by public footpath round 3/4 of the oval moat structure. There is also an inner moat that is not accessible. Private house(s) established on the site. It is listed in "Anglo-Saxon England" (F Stenton 1943f) as one site where King Athelstan held his council; and as a bequest of King Alfred in Anglo-Saxon Charters, S 1507: http://hwaet.heroku.com/charters?range=1482-1539 However other resources date it back only to the 12th century. Local, unsubstantiated, claims are that King Harold II's army camped here before Hastings. The photos only show the moat and low mound inside, and that is all that is currently accessible.