The quintessence of Baroque architecture, this church has a veneer that is beautifully rich concave spaces, dovetailed stone and marble, and mélange of bell towers. It's the production of Francesco Borromini (1599–1667), a contemporary and opponent of Bernini. Close to his new Pamphilj family castle, Pope Innocent X had the adjoining sanctuary ventured into this undeniable church. The work was first assigned to the planner Rainaldi. In any case, Donna Olimpia, the pope's famously tyrannical sister-in-law, turned out to be increasingly restless with how the work was proceeding to get Borromini, whose great curved passage has the supernatural impact of causing the vault to show up a lot bigger than it really is. The saint associated with the church is Agnes, who was martyred here in the piazza's trailblazer, the Stadium of Domitian. As she was stripped bare before the group, her hair miraculously developed to keep up her modesty before she was murdered. The inside is a wonder of particular Baroque space and is ornamented by monster marble reliefs sculpted by Raggi and Ferrata.