Rostau is a subteranean world, where human lives go after death. The word "Rustau" in ancient Egyptian means "the gate leading to the cross roads", a name that indicates the nature of that world, which is like a maze. Also the name of the corriders and secret passage ways that connect to many of the monuments in Egypt.
Here you are looking for a small orange container, a little bigger than a match stick case. As alway with my new caches, there is a trackable waiting for the FTF to pick up and move along. Safe caching!
Given coords are the starting point. There may be clues a short distance in each tunnel to let you know if you chose the correct path.