In both appearances, Corridor Number Two leads to the room with the Stone Statues or gates depicting Kraid and Ridley, which guard Tourian. It is a long corridor composed of the blue rock that makes up most of Brinstar, with several Koma statues and a small Acid pool. At the end of the hallway is a Red Blast Shield which leads to the Tourian access room.
Zero Mission expands the room and connects it to the corridor with the Long Beam through the ground. It is through here that Samus first enters this room. There are two extra Acid pools. After stepping into the gates room and returning, the doors lock. Samus enters an enclosed area and is confronted by a Dessgeega. Killing it is the only way to unlock the doors.
In the original Metroid, a Rio can be lured from this room into the Stone Statues room, frozen between where the bridge should appear and the acid, and then jumped off of, which allows Samus to access Tourian faster and without defeating Kraid or Ridley.