The church is located in the southwestern region of Washington Beach. The particular building wasn't known to be a religious institution until a search of the game files found otherwise.
The Secluded Church was confirmed to be a church in-game, but the reason for its seclusion is still unknown. Because the church has the look of a mere building, it took over a decade to find out that it is actually a church. It was revealed from the internal files of the game. Models and textures of this building are named as churchdoor1_256, churchwall6_256, churchwall3_256, churchwall2_256 and churchwall1_256.
This Church, unlike others in the GTA series, doesn't feature any towers or naves, but was built in a considerable scale and occupies a large area including an alley. Organ music can be heard from the Church, between 10-11 am.
The Church has the infamous Hexagram engraved on its stained glass window. A Hexagram is a frequently used symbol in many religious sects, so it isn't that surprising.