Question: Which canal is longer, the Shinnecock Canal or the Wiconisco Canal?
Context: Fæstningskanalen (literally "The Fortification Canal") is a canal in central Kongens Lyngby, Lyngby-Taarbæk Municipality, Copenhagen, Denmark.  Created in the 1880s as part of the new fortification ring around the Danish capital, it runs from Lyngby Lake in the west to Lyngby Hovedgade in the east.  From there it originally continued to Ermelunden in Jægersborg Dyrehave, but this last leg of the canal is no longer filled with water.  The project also included a more upstream straightening of the section of Mølleåen that connects Furesø in the west to the west side of Lyngby Lake in the east.  The canal complemented the West Rampart (Vestvolden) and a series of coastal fortresses which were built at the same time.  In the event of an enermy invasion, a dam at each end of the canal, one at Frederiksdal and one at Ermelunden, would be opened, and the natural drainage of Lyngby Lake would be blocked, leading to the flooding of an extensive area of land along Hvidørebækken all the way out to the Øresund coast.  Water would also be led through Gentofte Lake to Utterslev Mose, leading to further floodings.  Together with the moat in front of the West Rampart, this would create a complete water barrier around the Danish capital. The Wiconisco Canal was a 19th century transportation waterway, about 12 mi long, in Dauphin County in the U.S. state of Pennsylvania.  Running along the east bank of the Susquehanna River between Millersburg and Duncan's Island at the mouth of the Juniata River, the canal overcame about 42 ft of vertical lift through the use of 7 locks. The Union Bay Natural Area (UBNA) in Seattle, Washington, also known as Union Bay Marsh, is the restored remainder of the filled former Union Bay and Union Bay Marsh after University Village Shopping Center, the University of Washington (UW) athletic facilities, buildings, and main parking area (E1).  It is located at the east end of the main UW campus, south of NE 45th Street and west of Laurelhurst.  Ravenna Creek is connected to University Slough (Drainage Canal), thence to Union Bay, and Lake Washington.  Drainage Canal is one of three or four areas of open water connected with Lake Washington around Union Bay Marsh.  The canal extends from NE 45th Street, between the driving range and IMA Sports Field 1, south to the bay, ending southeast of the Husky Ballpark baseball grandstand (northeast of the IMA Building).  The Drainage Canal that carries Ravenna Creek past UBNA to Union Bay is locally sometimes called University Slough, though that is something of a misnomer in that "slough" is both used in the eastern and southeastern U.S. meaning, rather than the western U.S. meaning, and it is no longer a natural watercourse in that it is a canal that replaced bay and marsh, both now filled. The Canal de Beuvry is a canal in northern France connecting to the Canal Dunkerque-Escaut but no longer navigable all the way to Beuvry.  With the loss of the coal industry in this area, the canal is no longer used. The Shinnecock Canal (also known as the Shinnecock and Peconic Canal) is a canal that cuts across the South Fork of Long Island at Hampton Bays, New York.  At 4700 ft long, it connects Great Peconic Bay and the north fork of Long Island with Shinnecock Bay and the Atlantic Ocean.  The canal opened to traffic in 1892. The Saltisford Canal Arm is a short stretch of canal located in the town of Warwick, Warwickshire, England.  Opened in the 1790s, originally it wasn't an arm at all, but the start of the Warwick / Birmingham Canal.  It took on the appearance of an (arm) branch when the Warwick / Napton canal, which junctions at the Birmingham Road / Budbrooke Industrial Estate, was completed.  It is the last surviving branch (arm) of the much longer, nationally known Grand Union Canal. Bridge in Reed Township, originally known as Wiconisco Canal Aqueduct No. 3, is a historic multi-span stone arch bridge spanning Powell Creek on State Route 147 (River Road) in Reed Township, Dauphin County, Pennsylvania.  It was built in 1840, as an aqueduct.  The property measures 72 ft long by 50 ft wide.  It is built of red and white coursed ashlar and features a belt course and continuous parapet cap. Canoe Place was a station stop along the Montauk Branch of the Long Island Rail Road and first opened as a low cinder platform on the south east side of Shinnecock Canal around 1935.  The station was in service for "Fisherman's Special" trains and was closed around 1953.  The station was located between Hampton Bays and Suffolk Downs Stations.  The hamlet where it was located is now part of Hampton Bays, New York. Obvodny Canal (Russian: Обводный канал , lit.  Bypass Canal) is the longest canal in Saint Petersburg, Russia, which in the 19th century served as the southern limit of the city.  It is 8 km long and flows from the Neva River near Alexander Nevsky Lavra to the Yekaterinhofka not far from the sea port.  The canal was dug in 1769–80 and 1805–33.  By the late 19th century, after to the Industrial Revolution, it had effectively become a sewer collecting wastewater of adjacent industrial enterprises.  Eventually the canal became shallow and no longer navigable.  The banks of the canal are lined with granite. Fletcher's Canal was a 1.5 mi long canal in Greater Manchester, which connected the Wet Earth Colliery to the Manchester, Bolton & Bury Canal at Clifton Aqueduct.  The canal is now derelict and no longer used.
Answer: The Wiconisco Canal