Tomba of the Greats

This area is found just outside the foregarden of The Castle of Brass. The area is relatively small, but allows access to many other areas via underground tunnels. It acts as a short-cut to and from The Caste of Brass, at relatively high risk. The area is filled with several enemies that can inflict Magic-Rust, making magic builds especially vulnerable here, and dealing corrosion damage, which is very hard to deal with at the time most players will enter here.

Entering the Tomba
It requires the both the Mouthpiece of the Dead and the sheet music for Cleric Brass's Ballad in order to enter through the mausoleum. This means you must defeat Cleric Brass AND Skeletuba, meaning this area is accessible mid-game. When the mouthpiece is placed in the socket, and the ballad is played using it, the sarcophagus will fall through the floor, revealing the entrance to the area.