Church of Nossa Senhora da Pena or Church of Santa Maria da Pena was the first temple in Leiria, being documented in the 40's of the 12th century. This castle chapel was completely redone in the reigns of D. João I and D. Manuel I, with nothing left of the original design. The church has a single rectangular nave, with a nave and chancel in Gothic style, accessed laterally by an ogival portal of five archivolts supported by smooth columns. The polygonal apse reveals a covering of ribbed vaults with 7 panels. The side panels of the chancel are torn by double-edged ogival cracks, topped by quads. It was used as a palatial chapel by the Avis Dynasty. In the choir we can even see a Roman stone from Collipo, dedicated to the emperor Antonino Augusto Pio, and leaving the Manueline sacristy we have access to the ruins. A Gothic example of rare beauty, Sta.Maria da Pena existed around 1135-1140 and was the mother church of the Priory of Leiria, administered by the canons of Stªa Cruz de Coimbra, until 1545. Between the end of the century. The palatial chapel was adapted from the 14th and early 15th centuries, from which the chancel stands out, which evokes the heraldic symbolism of D. João (1383-1433), through the Gothic acronym "y" in its capitals and in the vault. . The two side tombs served lords and mayors. In the first half of the century. XVI suffered improvements, of which remains the sacristy with Manueline corbels. In the nave of the church, to the west, a Manueline arch that was transposed there in the 1930s evokes Stº António do Carrascal, an ancient peri-urban chapel in Leiria.