Ancients Awakened/Cavern of the Worm King

The Cavern of the Worm King, also known as "Greed's Hoard", is a large cave that generates upon world generation in the cavern layer. It is where resides. It contains the in the center. The Desire Altar can be used to summon. There are also 15 s that reside on island-shaped bricks. Each chest includes golden loot, and either one of the items obtainable from Pirate Invasion or 2 new weapons. Opening 3 of the chests will also summon.

The Cavern of the Worm King will always be generated at the same location, depending on map size:

Trivia

 * Despite being a structure, when nearby this place, the background changes to a darker set of rocks with gold ore inside.