Under Torah law, observant Jews are not permitted to carry objects from their own homes into a public street on the Sabbath. However the area defined as constituting a person's home can be formally extended through the creation of an Eruv. In mid-September 2012 Vienna witnessed the marking out of an Eruv in the capital for the first time since before the Nazis came to power. It roughly corresponds to the area of the central districts (first to ninth and the twentieth districts) and is bordered by the outer ring road and the Danube. For orthodox Jews this domain is now considered to be part of their private sphere, meaning that the ancient laws forbidding transporting objects from within the home do not apply within its confines.
The border of the Vienna Eruv is about 25 kilometers in length and consists of walls, fences, wires and natural borders such as the River Danube. For the uninitiated the Eruv border, which is regularly checked for gaps and breaks, is practically invisible as it is made up of existing wires and cables such as tram overhead electrical lines. The boundaries of the Vienna Eruv can be viewed at www.eruv.at.