MB4 210a: Disposing of Wastewater on Shabbos in a Carmelis (357:3); Status of an Enclosed Large Yard (358:1 - part 1)

Disposing wastewater in a carmelis. Pouring water from your courtyard into a pipe that empties into a חצר שאינו מעורבת.

Disposing wastewater in a walled city without an eruv.

Areas that are larger than בית סאתיים that are enclosed for purposes other than dwelling (e.g. an orchard). What about a shul or a jail?

Status of an area with natural "walls".