Built in 1557 by the Company of Santa Maria della Consolazione under the title of the Desert and of San Mercurio, formed by aristocrats, who venerated, in this chapel, an ancient image of the SS. Virgin, found in a deserted place outside the city walls; they had the task of helping the sick of the Great Hospital.
The room, preceded by an elegant staircase built in 1719 and by an anti-oratory with a majolica floor and a frescoed ceiling depicting “Jesus Christ visiting San Mercurio in prison”., Has harmonious stucco decoration around the windows and in the cappellone, executed by Giacomo Serpotta in 1678 and the classic arrangement of wooden benches along the sides.
On the entrance wall there is a choir with an organ in lacquered and gilded wood. The vault of the presbytery was decorated with a glory of stucco putti and frescoed with the “Glory of San Mercurio”, while on the high altar stands an eighteenth-century canvas depicting “The Apparition of the Virgin and Child to San Mercurio”. The majolica floor of the main hall was built between 1714 and 1715 by Sebastiano Gurrello and Maurizio Vagolotta based on a design by the priest architect Giulio Di Pasquale.