I had recently recommended the album, Sunken Cathedral, to a friend. The one I was referring to isn't streaming - it's an LP by Jackson Berkey and it's stupendous, I own two copies. They're cheap as chips. So if you have a record player, I encourage you to eBay your way to a $10 LP that will satisfy.
However, while looking for the Berkey recording on Qobuz this other "Sunken Cathedral" emerged. It has nothing in common with Debussy's work (as far as I can tell), save for the title.
But what serendipity!
The music defies categorization. Part ambient, part mindscape, fairly 'cinematic' in a way ...
Turn off the lights, maybe grab an adult beverage, and listen through the whole thing nonstop. It's phenomenal.