As promised here is the key to the map posted earlier this week. I am afraid the mountain lion encounter is what gave this dungeon it's killer reputation. He's a bit more than a first level fighter can handle.
The Ruins Above Ground
General: The ruins of Thetra lie half a mile east of the village of the same name. The whole area is covered by drifting sand. Taking the road which lead west from the village, the party will round a large sand dune and come upon a ruined wall with a 20’ wide opening in it. The road leads through the opening.
1. 10’ high walls crenelated though many of the merlons are missing with a walkway on top. Generally in a bad state of disrepair
2. Large courtyard paved with flagstones
3. 30’x30’ one story stone building with a pyramidal shaped roof of slates. In each wall there are 3’ 6” tall 6” wide arrow slits.
4. Staircase leading 15’ down to a set of oaken doors studded with iron spikes. The doors are shut and appear to be barred from the inside
5. Ruins of a large tower wall ranges from 10’ to 15’. In the SE corner 10’ up is a 3’ wide 5’ high arched window. The top of the arch is broken off. Next to the window is a staircase going down. The sill of the window contains a secret compartment with a large iron key and a small gem
6. The trapdoor will drop a person stepping on it 20’ into a corridor heading N and E
7. Bones of some large reptile, probably a dragon, buried in the sand. Underneath the dragon are the skeleton of a man, some pieces of chainmail and a broken corroded sword carved with strange runes thrust into one of the vertebrae.
8. A great gnarled tree. Around the base of the tree will be found the bones of wild animals. Occasionally a freshly killed animal will be seen hanging in the branches. There is a secret door in the trunk which leads to a ladder going down.
9. In this depression are the burrows of a band of 18 desert foxes. One of the burrows leads to first level. All of the burrows are large enough for a small man to crawl through, and can be enlarged fairly easily. There is a 1 in 10 chance of finding the right tunnel without the foxes help and the 8 adult foxes will attack anyone who tries.
Encounters (roll a six sided die)
1. Old man with a sieve sifting sand. Old man is a 9th level MU. He searches for the ring of the netherworld. If the party helps him there is a 1 in 100 chance a party member will find it.
2. A party of 7 men, 2 dwarves, a mule and a camel collecting dragon bones. Men are a 4th level mage, a 3rd level Cleric and five second level fighters. Dwarves are 3rd and 6th level fighters.
3. 1-4 foxes. These will run off towards the west (see 9)
4. Mountain lion lurking in the oak (8). He will attack anyone who investigates the oak too closely
5. Large beetle crawling across the flagstones of the courtyard. The beetle is metallic blue with a faint outline of a face on its back. The beetle is a polymorphed 8th level magic user.