Église Notre-Dame de La Réal is a royal parish church with roots in the early 14th century, built on the site of an older convent. Like much of Perpignan, it carries the layered history of Catalan, French, and revolutionary periods: it was even used as a munitions factory before becoming a church again in 1804.
The church is worth including on a walk through the old centre, especially if you are tracing Perpignan's religious architecture beyond the cathedral. Inside, look for the retained medieval and later furnishings rather than expecting a grand showpiece.