From PathfinderWiki

Vonosh was founded in 3314 AR after the Winter War to serve as the provincial capital of Hoarwood. In 3444 AR, Queen Morgannan razed the city to the ground in a storm of fire and ice and executed all residents of Vonosh — regardless of guilt or innocence — for their part in a plot to overthrow her and in retribution for the death of her daughter.123

Following the Hoarwood Rebellion in 3445 AR, the Heralds of Summer's Return tried to use the ruins of Vonosh as a base for guerrilla strikes against the new provincial capital city of Hoarwood. The plan failed because of the angry, restless spirits of those who had been executed by the queen. Some of the Heralds did not escape the attack of the spirits inhabiting the ruins.23