Considered the "Jewel of the Canal", the seven-arched 569 foot Monocacy Aqueduct has undergone a restoration effort to save it. It crosses the Monocacy River as it empties into the Potomac.
Most of the structures on the canal were made of sandstone and limestone but the Monocacy was made from pink quartzsite from nearby Sugarloaf Mountain.
It is the largest of the 11 aqueducts on the canal, being built from 1829-1833 at a cost of $127, 900.
Two attempts to destroy this aqueduct on orders from Gen. Robert E. Lee failed to bring it down. They were, however, able to destroy nearby locks.