Beyond Castle's Dungeons is a mod for registered Wolfenstein, made by Mario Maniac. It was released on October 12, 2003.
It features 16 levels, all very heavily guarded. The mod was mainly lifted from Castle Totenkopf v1.2, using many sounds and graphics therefrom.
The level of difficulty was quite high, as ammo and health was scarce. As such, a revised easier version was released on December 7, 2003. This version would in turn completely replace the original version.