Originally posted by Ryxzr:

So im new to this game and i recently got the swamp key but i cannot find a sunken crypt FOR THE LIFE OF ME. I have spent quite some time exploring to find swamps but every swamp i have been to doesnt have any crypts... is there like a special way to find them or am i just unlucky

They seem to have a weird spawn rate, some swamps will be full of them while others have literally zero, just go find more swamps.