Luigi entered The Courtyard after defeated the evil phantasm Bogmire. Upon entering Luigi was harrased by Flying Fish and (despite their being no ceilings) Ceiling Surprises, but Luigi ever vigilant managed to suck up the giggling ghouls and turn on the lights. After some exploring Luigi came across an old equipment shed which when opened unveiled a toad who after convincing Luigi to enter The Bottom of the Well saved his progress.
The Cortyard has many statues in it and also some crooked trees located all around it. There is the above mentioned shack and what is probably the Courtyard's biggest point-of-interest is the large fountain in the middle of it which Luigi can suck up Water Element Ghosts from. Last but not least is the well where Luigi manages to catch a glimpse of what befell Mario.