River Swilly

River Swilly
The mouth of the River Swilly near Letterkenny
Native nameAn tSúileach
Location
CountryIreland
Physical characteristics
Source 
  locationGlendore Mountain, County Donegal
  elevation~15.2 m (50 ft)
Mouth 
  location
Atlantic Ocean at Lough Swilly
Length~41.8 km (26.0 miles)

The River Swilly (Irish: An tSúileach) is a river in County Donegal, Ireland, which flows in an eastern direction through Letterkenny. Letterkenny, the largest town in County Donegal, is built on the river and became the first crossing point on the river in the 17th century.