1 — is a naviduct that carries the Chesapeake and Ohio Canal (C&O) over Seneca Creek in Montgomery County, Maryland.

It is located at the end of Riley's Lock Road in Seneca, Maryland.

Local residents had "a ball" fishing out the watermelons floating in the basin.

The National Park Service has since shored up the aqueduct with steel beams.

The aqueduct is included in the Seneca Historic District[5] in Montgomery County, Maryland.