"Hinterland" is another region-specific detective series. I'm calling it that because I watched "Shetland" a couple weeks ago. And right after I watch a detective series set in the Shetland Islands, I find one that's very specifically Welsh, with the name telling you that this is out in one of the less populated areas of Wales (around Aberystwyth). Wikipedia claims that there was even political intent behind funding a Welsh-specific series.
DCI Tom Mathias (Richard Harrington) is new in his department - but no introductions, he just goes straight to work. He's a bit of a grumpy bastard, but a good detective. And he's been fortune enough to inherit a competent crew. The first season is four episodes of 90 minutes each (I'm watching on Netflix, who take a particular delight in not showing British TV shows in their original format - this was originally broadcast as eight 45 minute episodes), each episode a case to be solved. It's implied that Mathias has a backstory, but not a word is spoken about it in six hours of the first season: he's just kind of grumpy and isolated.
I kind of enjoyed "Shetland." I'm less certain about "Hinterland," although as I'm writing this review I've already watched season 2. I'm most interested in the mysteries - not the detective's brushes with death, or their saving another victim within moments of death, and this show is fairly fond of both those tropes. See also Detective Stories in TV and Movies.