The Thorn (Fallout: New Vegas)

The Thorn is an underground settlement. The R in the sign is pointing to the sewer, letting you know that is the main entrance. The main draw of Thorn is the Arena, where you can bet on the outcome of fights between Wasteland creatures or fight in the Arena yourself. Next to The Thorn is the entrance into Westside.

Layout
In the middle is a large Arena, and surrounding the sides are cages with Wasteland creatures grown & kept by Red Lucy for Arena battles.

Bugs

 * Crash-to-Desktops are very common in this area, especially while fighting in the Arena. Save often.
 * After defeating any animals in the Arena, the doors open allowing you to leave. A second or two later all the gates that just opened for you to leave instantly seal and the only way out is through the side of the Arena, which itself is sealed unless this glitch occurs. This can easily cause you to get caught in between the two doors leading into the Arena with no way out except the console. This doesn't happen every single time but it's extremely common.
 * When betting on a fight between two giant mantises, the creatures enter the arena and do absolutely nothing (as if not hostile to each other). Red Lucy is unable to be interacted with and the fight remains a permanent stalemate, unless you want to shoot one and have Thorn turn hostile.

Appearances
appears in Fallout: New Vegas.