Be fair... Lets try not to look it up! But this could be a hard one... Unless you're me. lol!
"In my mind's eye, I see, three circles joined in priceless, graceful harmony. Two full as the moon, one hollow as a crown. Two from the sea, five fathoms down. One from the earth, deep under the ground. The whole, a mark of high renown. Tell me, what can it be?"