In 1974, we had no examples from dungeons. They weren't really a thing in fantasy literature - Gygax & Arneson basically made them up from whole cloth. Yeah there was Moria, but I don't remember a lot of treasure in Moria, plus Gandalf stole all the xp.
Lucky for our group one of our number proved a creative and cunning DM. He created a dungeon 6 levels deep with an elevator room in the middle that went to a random level (roll 1d6). We quickly learned to avoid that room.
He also placed a circular hallway around the entire dungeon which slowly spiraled down to the bottom floor, which had a teleporter to return you to the top. Rolling down that hall was a steamroller with a statue on top which kept you from spending too long there. Sometimes we met wandering monsters in the hall and mid-fight the juggernaut owuld show up and we had to flee or end the fight fast.
He even put a "real" dungeon on the 2nd level, complete with cells, manacles, and prisoners. Some of the prisoners were justly imprisoned, and some were not and it wasn't to tell which were which. We left the medusa there though, after she stoned one of our party.
He let me use his dungeon when I was the DM and I got lots of cool ideas from it.