I picked up Van Richten's Guide to Ravenloft and have been reading it cover to cover. This is my review of the book, chapter by chapter. Chapter 3 covers over 30 domains, so I'm posting about it as I work my way through the different domains.
Lamordia is a frozen wasteland, in the process of being desperately tamed, or at least obstinately defied, by its hearty population. Speaking of hearts, it's also the home of demented scientist Dr. Viktra Mordenheim, whose hobbies include stitching body parts together and animating them. If you're tracking tropes, this is the Frankenstein trope, but with some interesting new 5e twists.
In 3.5 Ravenloft, Dr. Mordenheim was almost a carbon copy of Dr. Frankenstein (depending on what source you consider canon, but I'm a Hammer Horror fan myself), with an animated corpse monster called Adam. In this book, Dr. Mordenheim hasn't exactly built a human from parts, but instead saves her dying assistant Elise by implanting an artificial heart, called the Unbroken Heart. The Unbroken Heart isn't magical, it's actual (steampunk) science, so it's considered to be a pretty big deal. Unfortunately, Dr. Mordenheim did a lot of murdering as part of her experiments earlier in her career, and just as she's finishing the implant, constables burst in to arrest her. She awakens in Lamordia.
Dr. Mordenheim's story is refreshingly clear. We don't know what world the "real" Lamordia is on, but we understand when Dr. Mordenheim crosses over from the real world into Ravenloft. Elise, or the Ravenloft version of her, wanders the landscape of Lamordia, lost in every sense of the word. Rumours spread across the land of, essentially, a flesh golem wandering the countryside, with a heart you can see glowing red from within it. No matter how hard Dr. Mordenheim tries, though, she can't track down her missing Elise, nor can she recapture the science of the Unbroken Heart.
To add to the macabre, Dr. Mordenheim experiments on whatever she can in her spare time. For instance, she can perform successful brain transplants. She has the brain of a local politician in a jar.
Dr. Mordenheim is, like the reborn lineage presented in Chapter 1, the perfect solution to a total party kill (TPK). A whole party can be resurrected in Dr. Mordenheim's lab, with any number of modifications either having been made or about to be made.
Lamordia itself is a great setting. As with all the other domains in this book, my first instinct is that there's not enough of it. However, there's a 3.5 Gazeteer with some additional details about Lamordia. Additionally, there's an icy north setting available from Kobold Press called the Northlands and a whole (unrelated) adventure path from Frog God Games called the Northlands Saga. Both of those are for Pathfinder, but I find the conversion from 3.5 to 5e pretty easy as long as you use monsters and traps and rules from the 5e Dungeon Master's Guide (DMG).
Lamordia is an excellent domain. It fits into classic horror, with allowance for as much grotesque elaboration as you feel appropriate for your group. It gets bonus points from me for being set in the frozen north, which is a motif I personally love, and I'm eager to run an adventure there.