The Lockwood Cellar is located underground in the woods at the old Lockwood Estate that was burnt down many years ago.
In Bad Moon Rising, Mason sneaks away to the cellar but Tyler follows him. He discovers an old, dusty room with claw trails and chains. Later Tyler asks his mom about the cellar, but she replies that they don't talk about the old cellar because it was used during times of slavery. Later, during the swimming party, Tyler brings Aimee here for a rendezvous, while Mason is hiding inside. Mason manages to escape, and Aimee refuses Tyler, telling him that instead she has feelings for Matt.
In Kill or Be Killed, Sheriff Forbes tortures Stefan and Damon in the cellar with intent to kill them for being vampires.
In O Come, All Ye Faithful, Niklaus Mikaelson kills twelve unsired hybrids here.