Pitch's Lair

Pitch's Lair is an ancient palace that sunk into the ocean floor, surrounded by mud and rock. It's a huge underground base with multiple cages, bridges and escalators. The whole environment is built at an angle and it feels like it's falling off a cliff into an abyss. In addition, it has negative elements from all of the Guardians' respective worlds. For example, he has a globe, just like North does, to keep track of the belief of the world's children, but it's colored grey and black.

While this ancient palace is located in Venice, Italy, it has multiple entrances that connects it to different parts of the globe. One of this entrances is under a broken bed in the middle of the forest, not far from Burgess and Jack's Pond.

History
In the chapter books, Pitch has multiple lairs all over the world. In book 2, Pitch builds a lair close to the Earth's core, since light cannot reach it. After failing to obtain the spellbooks from Ombric's library, Pitch kidnapped Nightlight and the children of Santoff Caussen, holding them hostage in lead cages. The walls of this lair were coated in metal, the air reeked of sulfur and shallow pools of milky lava flowed across the floor. Here, Pitch's Fearling Army built weapons and armour out of molten lead to battle the Guardians with.

In book 4, Pitch uses the cave Nightlight originally imprisoned them in, to hide a sleeping Katherine, encasing her in a coal-colored slab of marble that had been carved into a coffinlike shape, until Sandman and Nightlight came to rescue her.