Source: wikipedia

An earthen mound, in Wiltshire, England, named the Marlborough mound and situated on the grounds of the Marlborough boarding school, has been found to date back 4,400 years, giving it a much longer history than most experts of historical England had suspected.

Located on the Old Bath Road which ran between Bath and London, the 19 meter (62 foot) high mound has served as the basis for a castle, a possible grave site for Merlin the Magician, home to a king, and most recently as a centerpiece for the boarding school of the same name. Over the years, many possible explanations for the existence of the mound have been offered, but nothing much was done to prove any of them correct.

Now, using carbon dating, a team led by archeologist Jim Leary, have taken samples of charcoal from deep down in the mound; the results of which date the mound back to the time of the construction of , possible sister mound Silbury Hill and other monuments created by early British tribes. The work was sponsored by the Marlborough Trust, which is seeking to preserve the tree covered mound (the worry is that tree roots are causing it to become unstable over time) while at the same time giving it it’s proper due.

Once the centerpiece of a Norman castle, dubbed the “Mount” built after the famous invasion that led to the last conquering of the Britain in 1066, the castle lasted for roughly four hundred years, but was eventually torn down and replaced by its owner at the time with a house that sat just next to it, which eventually formed the basis for the current boarding school.

The mound, sometimes known as Silbury's little sister (after the bigger and more famous artificial hill just outside of Avebury) is now believed to be the second largest artificial mound in Europe.
Now that its proper age has been determined, its likely archeologists and historians will begin to study the mound with a fresh eye, hoping to add more pieces to the puzzle of those early British tribes that worked so long and so hard to create such long lasting monuments.