Hjalti's Sword

 is a unique Ancient Nord Sword in. It's a quest item that is required to complete the quest The Ghost of Old Hroldan.

Possible locations
The quest is initiated by speaking to the Ghost of Old Hroldan who has been haunting Old Hroldan Inn, east-southeast of Markarth. After receiving the quest, the bartender of Old Hroldan Inn will direct the Dragonborn to one of seven random locations:
 * Broken Tower Redoubt
 * Bruca's Leap Redoubt
 * Deepwood Redoubt
 * Druadach Redoubt
 * Hag Rock Redoubt
 * Red Eagle Redoubt
 * Serpent's Bluff Redoubt
 * Sundered Towers

Trivia

 * Hjalti was Tiber Septim's original name.
 * Hjalti's Sword can be obtained before starting the quest, then the Dragonborn can just give the sword to the Ghost of Old Hroldan straight away.