Hall of a Hundred Hearths
The Hall of a Hundred Hearths is the largest hall at Harrenhal.
A Clash of Kings
While serving incognito at Harrenhal, Arya Stark tries to count the number of hearths in the great hall, counting thirty-three on one occasion and then thirty-five on another. Arya thinks the Hall of a Hundred Hearths could host all of Lord Tywin Lannister's army if he so desired. Tywin's captives eat at their own table in the hall.
A Storm of Swords
A Feast for Crows
Jaime is tasked with restoring order to the riverlands. When he returns to Harrenhal, he has Rafford gather the castle's occupants, including the garrison and captives, to the Hall of a Hundred Hearths for him to review. Jaime has fires lit in the hall so that his own men can eat, and he then has a private meal with Ser Bonifer Hasty in the Hunter's Hall.
Huge hearths lined the walls, one every ten feet or so, more than he could count, but no fires had been lit, so the chill between the walls went bone-deep.—thoughts of Jaime Lannister