Water in a flowing stream: Shabbat 121b; Eruvin 46a, 48a
Water in a pond: Eruvin 47b-48a
Water in the ocean: Eruvin 45b
Water in a cistern: Eruvin 45b
Water in a barrel which a person owns: Eruvin 97b
Water or salt absorbed into a piece of dough: Eruvin 97b
A Vessel which began Shabbat in a yard which was linked, via a joint Border, to other yards with which a merger was or wasn't made before Shabbat: Shabbat 130b; Eruvin 23b, 35a, 74a, 89a, 91a
A Vessel holding many large items, where part of the vessel is within an area, and part is outside: Shabbat 91b-92a
A Vessel holding many tiny items, where part of the vessel is within an area, and part is outside: Shabbat 91b-92a
Considering all adjacent roofs to be the "area" of a vessel which began Shabbat on a roof: Menachot 72a
Whether a pauper, or anyone, may establish his location by standing there when Shabbat begins, or by picking out a place he knows of, as opposed to placing a meal there: Eruvin 47a, 49b, 51a-b
What is a person's "location" if he was going to embark for another town before Shabbat, he stated his intent, and he was held back by another person: Eruvin 51b, 52a-b
Considering a house to be a single unit/location: Eruvin 42b
Status of a boat: Eruvin 42b-43a
May a person establish his location by looking at it from a distance and making a verbal declaration: Eruvin 49b, 49b-51a
May a person establish that a certain space will be his Mekom Shevitah, if it is larger than four cubits and there is no specially marked four-cubit segment in it: Eruvin 49b-50b