As a young teenager, I devoured books of Arthurian Legends. "The Crystal Cave" by Mary Stewart 1970 and "The Hollow Hills" also by Mary Stewart told from the viewpoint of Myrddin Emrys also known as Merlin. So, I was surprised to find that The Lady of Shalott was inspired by Alfred, Lord Tennyson's poem of the same name, written in 1832, and based on Arthurian Legends. http://en.wikipedia.org/wiki/The_Lady_of_Shalott
In my study of the Bible, I've also been surprised to find links to Arthur of ancient times, the Knights of the Round Table, and The Quest for the Holy Grail. "Traditions of Glastonbury" is a very interesting video and book on the subject written by E. Raymond Capt a Biblical Archeologist. This work also elaborates on Jesus' "missing years". http://www.geocities.com/regkeith/rkeith5b.htm
If The Stone of Scone, also known as The Coronation Stone and The Stone of Destiny that literally every king and queen of England, Ireland, and Scotland have been coronated over to this present day, and its FULL history is understood, then it is not too difficult to understand how all these topics intertwine in harmony. http://en.wikipedia.org/wiki/Stone_of_Scone
Could it be that those rings were how the Israelites carried that Stone, or "pillar" of Jacob for 40 years? Could that crack be where Moses struck the Stone, The Rock and precious Life Giving Water flowed out? Is there yet unfulfilled prophesy regarding this Stone?
If you follow the link on The Stone of Scone, you will see that The Stone has been overturned, overturned, and overturned and now resides in Scotland again.