Under the Radar - OLDENHELM
Don't let the name put you off, this is really good stuff.
California isn't the first place that springs to mind when you think of dungeon synth, but that is the origin of this project nonetheless.
The solo artist describes his music as 'medieval ambient'; and his work is recommended even if you wouldn't normally be allured by the 'medieval' part.
It does a great job of transporting you somewhere else - "through the embers of fading empires, mighty fortresses whose towers and iron gates pierce the sky, and desolate northern landscapes".
You can download the full digital discography (three EPs/twelve tracks, recorded 2016-17) for a very reasonable price on Bandcamp.
This material has only been released physically on limited edition cassettes.
You can also listen to a choice EP in its entirety below.