Techum

1. It is forbidden to walk beyond the Techum on Shabbat. In general, the techum is a 2000 Amot beyond the immediate 4 amot area around a person.

Determining the Techum

1. If a person is alone in the desert, the Techum extends 2000 amot beyond the 4 amot area him. If one is in a house, the Techum is 2000 amot from outside the house.
2. If one is in a village, town, or city, one may have 2000 amot from the outer bounds of the city, depending on the density of the houses. If there are 6 homes each within 70.66 amot of another home are considered a city and the Techum would begin from 2000 amot outside the group of houses. Any home that is within 70.66 amot of the established city is included in the city, however, a house which is more than 70.66 amot from other houses is not included in the city and the Techum for residents of that house is only 2000 amot from the edge of that house. Therefore, a suburban area with houses separated more than 70.66 amot are not considered part of a city and residents of a house only have 2000 amot from that house.
3. Many cities have 2000 from the edge of the city which are drawn as a rectangle along the directions of a compass, from the edge of the northern most house, eastern most house, southern most house, and western most house. However, if the city is already rectangle, L-shaped, or arc shaped may not have this extension of squaring off the city.
4. Because the laws of establishing a Techum and extending the Techum with a Eruv Techumin are complicated one should consult a local Orthodox Rabbi.

Walking to the edge of the Techum

1. It is forbidden to walk to the edge of the Techum in order to leave on a journey quickly after Shabbat. However, if the action one is going to do after Shabbat could theoretically have been done on Shabbat, it is not forbidden to walk tot the edge of the Techum waiting for the end of Shabbat. For example, one may walk to the edge of the Techum in order to bring one's animal back because theoretically one could have done this on Shabbat if there were houses extending the Techum. Also one may walk to the edge of the Techum in order to collect fruit which fell before Shabbat and aren't Muktzeh because theoretically one could have done so on Shabbat if there were walls surrounding the path (which would permit carrying on Shabbat).
2. One may walk to one's garden within the Techum in order to pick fruit after Shabbat since it is not evident that one is walking there for that purpose.