Dorateen
Arcane
Old school dungeon crawlers were defined by their problem solving approaches. Not only map making, but also puzzles and riddles and requiring players to figure things out for themselves, without developer hand holding. You don't find the type of navigation obstacles in modern cRPG design that the classics had to create challenging gameplay.
I will admit it might be the issue that I simply haven't played the games with the best puzzles in the genre. But in my experience, the puzzles in this type of game are of a much more limited sort. Stuff like finding levers, hidden secret buttons, understanding how levers affect each other, etc. Don't get me wrong, this can be a whole lot of fun! But it fall short of the stuff you might have even in a simple module like the B1: In Search of the Unknown.
The first dungeon the party can enter in Might & Magic II introduces the player to scrambled messages that need to be decoded. This is done by finding various interleave messages, scattered throughout a sprawling gameworld, that are used to unlock the proper sequence of letters.
Bradley's Wizardries were notorious for making the player stumble across inventory items and divine their use, often required for some other remote location or far away map; or track down NPCs to interact with through the keyword parser. The kind of things that makes the player pay attention and take notes, ponder their discoveries and engage in problem solving.