I'm currently reading "The Templar Meridians" by William F. Mann. It is a pretty interesting non-fiction book about the Knights Templar, Freemasonry, the search for the Holy Grail, and how it intertwines with the history of the new world. From the back of the cover;
"The most enduring mystery surronding the Knights Templar concerns the nature and final resting place of their great treasure. Whereas many believe this lost treasure contains knowledge of the holy bloodline - including the wherabouts of its decendants - William F. Mann shows that it may in part consist an ancient science developed before the great flood, one discovered by the Templars in the Holy Land during the crusades. Still extant in Masonic/Templar ritual today, this knowledge enabled the Templar Order to establish accurate latitudinal and longitudinal positions long before the seventeenth century, when the foundations for geographic sciece were laid. It also allowed the Templars to cross the Atlantic and reach the new world, where, led by Prince Henry Sinclair, they established both secret setlements to protect the descendants of the Merovingian dynasty and mining operations that gave them a limitless supply of precious metals and a military edge over their opponents.
Persued ever farther into interior of the North American continent by their adversarys from the Old World, the Templars left artifacts, relics. and information at key sites in the hope that future initiates could use their understanding of the science of meridians and ley lines to locate these caches. As Mann demonstrates, the history of the search for these Templar treasures has been intimately intertwined with the history of the United States and Canada, from the time of the first European explorers, the American Revolution, and the design of Washington DC to the Lewis and Clark expedition."
Not really my cup of tea, by still a very interesting read.