Simbahang Bato (Naujan)
Philippines
The Bancuro Church, locally known as Simbahang Bato (transl. Stone Church), is a ruined Roman Catholic church located in Barangay Bancuro, Naujan, Oriental Mindoro, Philippines. It earned the moniker "a church within a church" because a small chapel is currently housed within the ruins' massive walls.
Church data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).