The Igreja do Santíssimo Milagre is built on the site where, in 1247, the so-called Miracle of Santarém is said to have occurred — one of the most celebrated Eucharistic miracles in Catholic tradition. The church has been a pilgrimage destination ever since, and the reliquary said to contain the miraculously transformed host is still venerated here.
The church interior is Baroque, rebuilt in the 17th and 18th centuries on the original medieval foundations. The reliquary chapel is the focal point of the space, decorated in marble and gold leaf. The church is central to Santarém's religious identity and is usually open for visits as well as worship.