This place is literally chock full of bones, skulls and death. It. Was. Awesome.
There were plenty of "chapels" and creative designs throughout.
Just some FAQs: it was not stinky, it was not damp, it wasn't spooky or creepy and the bones are not cemented down (as we found out by picking up one--however there is little temptation to take one while you are there...it just feels WRONG). It's deafeningly quiet. I kept whispering as if I would what--wake the dead? The lighting is poor so keep this in mind for photos and sneaking up on folks.
The weirdest part of the whole thing was running into other tourists. It seemed unnatural to see living flesh after an hour or so of wandering through the dead.
BTW once you get down there and panic, there is NO escape route. You commit to the whole journey (just not the sort of commitment the residents are held too. :)
If only they piped in Swedish Death Metal to complete the mood...