The Triclops Pit is a large cavern with metal grids covering the floor and a pipe that leads below the grids, small enough that the Morph Ball must be used. Underneath, there are multiple Triclops; following the path, there is another pipe leading to Storage Cavern. Above the grids, there are a few rock pillars. Platforms with Puffers around them lead up to the Monitor Tunnel door, some of which descend when Samus stands on them, and near the door to Pit Tunnel there are a few metal crates. Vents of red steam in parts of the room fog up Samus's vision for a short period of time if she steps into them.
- 5 Triclops
- 7 Puffers (Before Super Missile is obtained)
- 2 Flying Pirates (after Super Missile is obtained)
- Missile Expansion
- This is found inside a rock spire at the back of the room. It can be collected by finding the correct pillar using the X-Ray Visor and opening it up with a few Missiles or one Super Missile. Another method is to use a nearby ledge in the wall to reach the expansion, this can be done after acquiring the Space Jump Boots. There are some invisible platforms to use in order to aid Samus in getting to it; though, this requires the X-Ray Visor.
- The Triclops Pit's internal file name is "14_over_magdolitepits". As "Magdollite" is the internal name of the Magmoor creature (and a different creature in Super Metroid and Metroid: Other M), it is possible that Magmoors were in this room at one point.