This room is composed of the same blue rock material as the majority of Brinstar, with noticeable stalactites on the ceiling. It initially appears to be a square room with a single "platform" in the center, partly composed of four Bomb Blocks. There is a shaft below. In the original Metroid and Zero Mission, Samus requires the Bombs before she can access the lower shaft as the floor is composed of Bomb Blocks, although she can shoot the blocks in the platform with the Wave Beam (in Metroid) or with aimed shots (in Zero Mission and Super Metroid). In Metroid, there are two more lines of midair blocks, but these do not have to be shot and Samus can simply step off them, while shooting through them to get back up.
The shaft below has a Blue Door at the very bottom, directly connected to the elevator to Kraid's Lair. In Metroid, the shaft is very long and lined with multiple midair platforms, which are teeming with Zoomers and Geemers. There are also several Rippers and Ripper II flying beside some platforms.
In Victory Techniques for Metroid, Samus comes to this room after defeating Ridley first, and rolls in between the destructible blocks. Surprised by a Geemer, she lays a Bomb to destroy it, uncovering a hole in the floor in the process.
In Zero Mission, to account for the Game Boy Advance's reduced screen size, the shaft is shorter. There are now only five midair platforms, the two Fake Block long platforms under the floor are removed, and four ledges are added to the wall, one of which is a short slope. The room now appears to consist of some architecture, possibly Chozo, and the cave aspects take on the more rugged appearance that Brinstar has in the remake. A hidden Morph Ball launcher in the floor blasts Samus into the ceiling, where she can find a Missile Tank (see below).
In Super Metroid, the room retains its general appearance from Metroid, but adds two Koma heads to each side of the long platform above the floor. It has become desolate in the years since the Zero Mission, and is empty when Samus first arrives. Two Zoomers are present if Samus returns here after being detected by the Eye scanners in the adjacent rooms.
Samus can crouch and shoot to break all of the Fake Blocks in the platform, without using the Wave Beam. The two fake platforms below are retained, but the room is much shorter and the door to Kraid's Lair is no longer accessible. There are two Koma heads in the shaft as well, and there appear to be pipes and bricks in the walls of the room. There is now an overhang to the left with a crevice underneath that Samus can fit through with the Morph Ball. Through here is a door to a small room with a Chozo Statue holding the game's first Missile Tank.
- Corridor No. 1 (via Blue Door)
- "Overhang corridor" (via Blue Door in Metroid and Zero Mission, Pink Gate in Super Metroid)
- "Transport to Kraid" (via Blue Door in Metroid and Zero Mission)
Metroid: Zero Mission
- 2 Zoomers
- Missile Tank
- Zero Mission only; on the very bottom ledge, Samus must lay a Bomb to reveal a Morph Ball launcher. This will fire her into the ceiling, which has the Tank.
- BOMB AND DROP (pg. 130)
- "You may be tempted to blast through the blocks near the starting point as soon as you collect the Bomb upgrade, but you should wait until you have a few Energy Tanks, a good collection of Missiles and the Varia Suit. The shaft that you'll drop into leads to the lair of one of Zebes' most feared creatures - the spike monster, Kraid."
- 002 UNCOVER ENVIRONMENTAL SECRETS (pg. 27)
- "You can blast some blocks out of the way with your beam, revealing passages to new areas. Some blocks also buckle under your weight when you stand on them. After a block is gone, it may remain out of the picture as long as you are in the area, or it may reform over time.
- If your beam can't destroy a block but the block is bombable, a beam shot will reveal the block's weakness. As you collect more weapons, you'll gain the power to bust through more obstacles."
- 067 HAVE A BLAST (pg. 43)
- "At the start of the game, you may have noticed a line of bombable blocks on the floor of a one-screen-wide room. Return to the room and use bombs on the floor to gain access to the area below."
- 068 missile tank (pg. 43)
- "When you reach the bottom of the short shaft, jump to the rock formation on the left side and detonate a bomb. You'll fall into a depression that contains a launching device. Roll into its cup and plant a bomb. After the bomb detonates, you'll take off.
- The launcher will lift you to the top of the shaft, where you'll see a Missile Tank in a cove to the right. Press Right on the Control Pad while you drop to roll into the cove."
The passage from the Metroid Prime guide is used almost verbatim on page 108. The final sentence is changed to this: "The shaft leads to the lair of the spiked monster, Kraid."