Fort Dawnguard is a location in Skyrim: Dawnguard
Fort Dawnguard is the headquarters of the Dawnguards
How to get there
Go southeast from Riften and through Dayspring Canyon
Fort was used by Jarl of Riften in Second Era, to contain his son who contracted Vampirism.
How To Get To Fort Dawnguard in Skyrim
A Tour Of Fort Dawnguard In Skyrim