Ancient Saint Mary church in Cambados, Gothic church ruins in Cambados, Spain.

The Ancient Saint Mary church, also known as Santa María de Dozo, is a roofless medieval church ruin in the historic center of Cambados, in Galicia, Spain. The standing stone walls still frame Gothic arched windows, and the interior functions as a cemetery with graves laid among the grass.

A Romanesque church existed here by 1421. In the 15th century Lope Sánchez de Ulloa began a Gothic replacement, which his daughter María de Ulloa, mother of Alonso III de Fonseca, enlarged and finished; Cardinal Jerónimo del Hoyo and Caamaño Bournacell date the works to 1470–1490. Worship moved to San Francisco in 1838 when the building threatened ruin; the wooden roof was removed, restoration stopped, and the facade later collapsed.

The cemetery remains an active place where local families honor their deceased with traditional burial practices and remembrance rituals. These customs show how the site continues to hold meaning for the community.

The site sits in the center of Cambados and is easy to reach on foot from the main square. Since the building has no roof, a visit on a dry day makes it easier to walk around the graves and read the stone inscriptions.

The parish cemetery that fills the churchyard and now spills inside the ruins was called by writer Álvaro Cunqueiro "the most melancholic cemetery in the world". The first restoration work came only in 1977, although the ruin was declared a National Monument in 1943.