Having recently started playing the Mausoleum, it wasn't immediately obvious to me that by entering through one of the south graves (the first you come to) that you go straight to level 'b', i.e. two levels down, bypassing level 'a' entirely (accessed directly from the north graves).

My suggestion is either to make it obvious you are going down two levels by passing through an intermediate mini-map, or else (better imo) make the four entrances go to level 'a', with ladders down (perhaps at different locations - so you have to work through 'a' first) to level 'b'.

response:
I am aware of this.  Due to the nature of that dungeon (81-110 mobs and easier than GT as all but the boss room are at default settings except level), it could have become another B3 DT situation where lower levels were barely surviving and higher levels come plowing through either killing everything on the way or luring on the lower levels.  I fully expect Lippy will modify that as his plan progresses, but that's his choice.

OK, I understand your reasons.  Maybe, however, the first pair of entrances (south) should go to level a and the north pair to level b. That way the first-timer is more likely to encounter level a first (unlike me ), but hl players can still gain direct access to level b.  I've not really studied the floor plan, so I don't know if it would just be a simple matter of changing the exits, or whether some redesign would be needed.

That would really confuse the regulars 

Or, with my initial suggestion, if the a -> b ladders were always next to the surface -> a ladders (as they are in one case iirc), there wouldn't be any running through.