This is the first major room of the underwater area of Maridia, and Maridia itself. It is a cavernous shaft similar to the entrance shafts of Brinstar, the Wrecked Ship and Norfair. This room differs from those in many ways, however: it is not vertically straight, as it curves up and to the left, and it only connects to doors on the right side with none on the left, with the exception of the entrance in the floor. Much of the shaft is ascended via crags in the walls, with nine midair platforms near the bottom of the shaft. Much of the ground is covered in plants that resemble a hostile species witnessed only on Bryyo. Some of these extend into the background. Mysterious, floating geometric towers with pyramid-like ends can be seen extending into the far background. Their purpose and origin is unknown.
It is possible to collect two expansions in this room. The first is a Missile Tank embedded into the ceiling, which is sealed in by a Boost Block. To reach it, Samus must run in an adjacent corridor until her Speed Booster activates, and quickly enter this room. On the ground next to the entrance door, there are two plants that appear prominently in the foreground. Samus must stand over the leftmost of these plants and Shinespark straight up; if done correctly she will fly past the midair platforms and straight into the tank in the ceiling.
- "Glass Tunnel" (via Blue Door)
- "Underwater runway" (via Red Hatch)
- "Fish pits" (via Blue Door)
- "Mount Death" (via Blue Door)
- Missile Tank
- See above.
- Super Missile Tank
- See above.
- A. GET A BOOST (pg. 96)
- "Shoot the door on the right, enter the corridor, defeat all of the enemies there and open the gate. Use your Speed Booster to Dash from right to left through the door. Press Down, then jump from point A to reach the Missiles above."
- B. TUCK AND ROLL (pg. 97)
- "Press Down to morph into a ball, then roll from point B down the wall. If you keep holding Left on the Control Pad as you fall, you'll roll into a secret passage that leads to Super Missiles."
1. SECRET SAMUS' BALL (pg. 65)
- "Roll into a ball then drop off this ledge, and keep holding the pad to the left. You should enter a hidden tunnel about half way down, leading to extra goodies."
- 2. HEAD BANGER (pg. 65)
- "Here's a tough section that will probably take a few attempts to get right. You need to clear a path to the right, long enough to build up power for a super jump. You also have to time the jump to miss the series of barriers above! Get it right and you'll fly into the rock overhanging high above, emerging with a set of missiles for your pains."