The shrine of Santa María served as the parish church to the old village of Peñalba, today abandoned. It is one of the few Mozarabic buildings still surviving in Spain.

The shrine is located in an area near the village of Arnedillo, and is built from masonry work, possibly dating from the 10th century. It has two naves in two sections which are joined by means of a central pillar, from which project four semicircular arches, in a design reminiscent of a palm tree.
It also has two apses, one in a horseshoe shape and the other square, which open onto the nave through two Visigothic-style horseshoe arches, framed by Mozarabic moulding.
On its interior it contains a 13th-century Romanesque carved figure of the Virgin of La Anunciación. It also had a front altar panel dating from the 12th century with a Romanesque painting depicting scenes from Christ's childhood (the Epiphany and the Presentation in the Temple).