Horn of Praecor Loth

The Horn of Praecor Loth is an artifact of great power which is used to free the denizens of Castle Britannia from their imprisonment in the Guardian's blackrock dome. It appears in  Ultima Underworld II.

Description
This magical battle horn belonged to Praecor Loth, the last king to reign of the world of Rhiannon before it fell to the Guardian. When it was blown, it had the ability to shatter buildings and flatten armies, although none save Loth himself were able to sound it. After the death of Praecor Loth and his people, the horn was buried in the tomb of the warrior king, where it lay for over seven centuries, despite the best efforts of the Red Titan's servants to claim it.

The Avatar would eventually recover this horn after laying Praecor Loth's wandering spirit to rest, and by binding an air djinn into their lungs, the hero would be able to make it sound. After numerous other trials, they would come to use its blast to shatter the dome of blackrock which encompassed Lord British's keep, freeing those who had been trapped within.

Trivia

 * Once the player has bound the air djinn within themselves, they may use the Horn of Praecor Loth like any other musical instrument in the game.