[3] The name means estate or farm of Theolf which is supposed to have been the original owner of these lands.

Of the rest of the land, 31% is settled (buildings or roads) and the remainder (1.9%) is non-productive (rivers, glaciers or mountains).

[4] The municipality is located on the eastern flank of the Lägern ridge at the entrance to the Wehntal.

Most of the population (as of 2000[update]) speaks German (84.2%), with Italian being second most common ( 4.0%) and Albanian being third ( 2.7%).

[4] The historical population is given in the following table:[3] Dielsdorf railway station is a stop of the Zürich S-Bahn on the line S15.