I'm looking for suggestions for horror-themed books (can be of adventure, fantasy, sci-fi or other genre) which are based around the protagonist either exploring or escaping from large, complex and mysterious locations while encountering progressively scarier and more dangerous entities and other concepts. This type of story seems to be quite common in movies, video games, anime and similar media, yet I am wondering if there are decent books featuring a similar concept and providing for a long, exciting and also uncanny experience.
Random examples:
– scientists exploring a newly discovered ecosystem get stranded after an accident, and start encountering mysterious and terrifying creatures, places etc. while both looking for a means to escape and still gathering as much data as possible
– a squad of soldiers sent to deal with an unknown threat in an abandoned base or research facility, where they are attacked by monstrous creatures, and keep encountering more and more horrifying monsters the deeper they go
– supernatural investigators getting deeper and deeper into lovecraftian-style ruins, meeting ancient horrors and entities
by DangerCloseTuber