Many of the most famous bridges in early America appeared along the 
National Road in Pennsylvania. One such bridge is the famed "S" Bridge located five miles southwest of the town of Washington in Washington County. It was built to carry the road over the Buffalo Creek.
Made of stone, the "S" Bridge was completed and 1818 and named for its double-curve design. The reason that the bridge had this design was because it allowed the building crew to save on materials in construction. The two-span, arched bridge was constructed of stones gathered primarily from the stream below.
Bridges, such as the "S" Bridge, helped make the National Road a major thoroughfare for trade and travel in the Alleghenies region. Prior to the construction of the road and its bridges, crossing waterways of the upper Ohio Valley was significantly more treacherous and time-consuming.
The cache shouldn't be hard to find. I wanted cachers to stop and check out the bridge.