Uffington White Horse

I saw this while on a bike ride through southwest England in 1978.  Its about 20 miles from Avebury which we visited at the same time. The White Horse was built into the landscape around 1000 BC and has been maintained by local inhabitants for the past 3,000 years.  Now that's dedication.  I have not found any information on the mechanisms of memory and tradition that kept this ritual intact for so long.  The original purpose of the horse design remains unknown.  This article provides some additional background.