The datum is defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment. A total of 106,724 kilometers of leveling was involved, constituting 246 closed circuits and 25 circuits at sea level.
George Washingtonâs Mount Vernon is located roughly 15 miles south of Washington, D.C. and 8 miles south of Alexandria, Virginia on the banks of the Potomac River, at the southern end of the George Washington Memorial Parkway.
Buy Tickets Shop. Mount Vernon. General admission to George Washington's Mount Vernon includes access to the famous mansion, the beautiful view across the Potomac River, all the surrounding colonial buildings, Washington's amazing gardens, our farm, and museum filled with Washington treasures.