Seneca Aqueduct | |
 Aqueduct, with Riley's Lockhouse at upper right. | |
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| Nearest city | Poolesville, Maryland |
|---|---|
| Coordinates | 39°4′7.45″N 77°20′28.22″W / 39.0687361°N 77.3411722°W |
| Part of | Seneca Historic District (Poolesville, Maryland) (ID78001475[1]) |
| Added to NRHP | November 15, 1978 |
Seneca Aqueduct — or Aqueduct No. 1 — is a naviduct that carries the Chesapeake and Ohio Canal (C&O) over Seneca Creek in Montgomery County, Maryland. The C&O built eleven aqueducts along its 184.5 miles (296.9 km) length. Seneca Aqueduct is a unique structure, not only being the first built, but also the only red sandstone aqueduct on the C&O−and the only aqueduct that is also a lock (Lock 24, or Riley's Lock). It is located at the end of Riley's Lock Road in Seneca, Maryland.