Quote Originally Posted by Grey_Wolf_c View Post
No, the first ring of defence was the outside of the cave - a narrow bridge over a chasm. Second was the first barrier (anti-magic) with soldiers behind it. And the third the last barrier, that turned you to stone if you broke the rules.

Grey Wolf
Alternatively:

1) Orange Barrier that keeps foreigners, magic and foreign magic away.

2) Guards in the stairway.

3) Blue Barrier to prevent foul play.