The burned-downed church in True Detective was constructed for the show near the Bonnet Carre Spillway. The flats surrounding the levee were not easy to reach. As the True Detective production designer recalls in an interview with vulture:

“You had to get to it by driving down a service road over a levee, down a mud road, and then we even had to drop down gravel to make it reachable. There was a lot of, Is this worth it?”

The result was the toxic verdant green of a watershed swamp, pocketed with light reflecting off the refineries and industrial-sized construction.

Constructed in 1931 (and about 12 miles west of New Orleans), the Bonnet Carre Spillway allows floodwaters from the Mississippi River to flow into Lake Pontchartrain and out into the Gulf of Mexico.

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From wiki:
Carcosa is a fictional city in the Ambrose Bierce short story "An Inhabitant of Carcosa" (1891).

Its name may be derived from the medieval city of Carcassonne in southern France, whose Latin name was "Carcaso".

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A deteriorating Civil War fortress in Louisiana called Fort Macomb was turned into the Yellow King's Carcosa for the season one finale of HBO's True Detective.

During the war the site guarded the Chef Menteur Pass, a water route connecting the Gulf of Mexico to Lake Pontchartrain. It was decommissioned in 1871 and is currently closed to the public.

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Rust Cohle (as his alter ego Crash) infiltrates the Iron Crusaders and they attempt to rob a stash house in the Westwego housing projects in episode four of HBO's True Detective

When the robbery goes south Cohle drags Ginger through the house facing Lake St. and then the tracking shot follows them as they scale a fence between Texas St. and Emile Ave. before Hart picks them up.

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On April 23, 1991, Johnny Thunders (former guitarist for the New York Dolls and punk solo artist) died of mysterious circumstances in room #37 (now room #7) of the St. Peter Guest House in New Orleans, LA.

While the N.O.P.D. ruled the case an overdose, toxicology results indicated that Thunders had not consumed enough drugs to overdose. In addition, he had been recovering from addiction with methadone treatment for several months.

Dee Dee Ramone spoke to Thunders' rhythm guitarist, Stevie Klasson, after Johnny had died. Klasson stated that Thunders "had gotten mixed up with some bastards... who ripped him off for his methadone supply. They had given him LSD and then murdered him."

Thunders was 38 years old.

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