Step 1 The temple under the jungle
About 50 squares south-east of the Jungle temple walk down the ramp at 31500,32476 to floor 8. The ladder at the same spot on floor 8 leads back up.
Step 2 Three chests
The underground temple on floor 8 hides three chests, each from level 100: 10 crystal coins at 31564,32503 (east), a royal helmet at 31473,32520 (south-west) and a demon shield at 31531,32434 (north-east). Each chest opens once per character.
Step 3 Guardians
The pharaohs (Ashmunrah, Dipthrah, Mahrdis, Morguthis, Omruc, Rahemos, Thalas and Vashresamun) roam the halls together with ancient scarabs, marids, efreets and djinns - some of them stand right next to the chests.