Oreskirk Mine
I think any D&D game can use a good Mine Dungeon. I designed this Mine with a rotating platform Minecart System to give the players an environment they can play around with while in combat. It has several points of entry, including a hidden escape door and a ventilation system that can be used as a crawlspace.
Each area is also separated by enforced doors with support beams to prevent cave-ins, which can be used by an insightful player to achieve the exact opposite and have part of the roof collapse on his foes.
All the way in the back is a room used by miners to worship the God of fortune. It includes a couple of treasure chests and a golden holy symbol.