The parish church of San Sebastian, from the beginning of the 12th century, is in the Romanesque style. From its original structure remains the tower, part of the arch of the entrance door and a biforia window; and in its interior the presbytery of absidal form; totally renewed with a window at the end and a cornice of dice in all its perimeter.

It is also interesting the cover of three smooth arches, the central one resting on columns with simple Corinthian capitals. There is also a beautiful Christ hanging over the Romanesque altar. It is the site of the first burial of Blessed Juana de Aza, mother of Santo Domingo de Guzmán. In the small baptistery was baptized Santo Domingo. The baptismal font was transferred by Alfonso X to the convent of the nuns for safekeeping until 1605. Currently it is in the Monastery of the Dominican Mothers of Santo Domingo el Real , in Madrid, where members of the Spanish Royal House continue to be baptized.