Forte Castellaccio is an abandoned hilltop fortress in Messina, Sicily built by Juan de Vega, Viceroy of Sicily around the middle of the 16th Century as part of a defensive project ordered by Emperor Charles V of Habsburg.

[1] It was designed by the Italian military architect Antonio Ferramolino (died.

[4] Despite several attempts to renovate the site since, it has remained abandoned and considered locally to be haunted by the ghosts of orphans and by the apparition of a nun.

[3] The fortress stands on a hill between Gravitelli and Montepiselli, a short distance from Forte Gonzaga, another 16th Century defensive structure also built by Juan de Vega and designed by Antonio Ferramolino.

[3] The original structure has a quadrangular design and is annexed by several more modern buildings, all now in a state of dereliction.