Sewer A

The Sewer A is a location in Luigi's Mansion 3. It is found in the Boilerworks on the second basement floor of The Last Resort, located east of the Observation and west of Sewer B.

Luigi must ride inflatable duck rafts through the flooded sewers while avoiding mines, with Gooigi crawling through pipes and opening gates for him. Luigi must also open pipes for Gooigi.

This room is also revisited when Luigi escorts Toad.

When Luigi returns with Toad, he can reveal a machine and play music to complete the achievement.