The E1 zone (sometimes E-1 zone) or E1 area or E1 (short for East 1) (Hebrew: מְבַשֶּׂרֶת אֲדֻמִּים, Mevaseret Adumim) is an area of the West Bank within the municipal boundary of the Israeli settlement of Ma'ale Adumim. It is located adjacent to and northeast of East Jerusalem and to the west of Ma'ale Adumim. It covers an area of 12 square kilometres (4.6 sq mi), which is home to a number of Bedouin communities and their livestock as well as a large Israeli police headquarters. The Palestinian tent site of Bab al Shams, which was established for several days in early 2013, also lay within this area.
There are Israeli plans for construction in E1, named the E1 Plan, frozen since at least 2009 under international pressure. This plan is not synonymous with the expansion of Ma'ale Adumim. The plan was initially conceived by Yitzhak Rabin in 1995.
Construction in E1 is controversial. Critics say that the plan aims at preventing any possible expansion of East Jerusalem by creating a physical link between Ma'ale Adumim and Jerusalem, and that it would effectively complete a crescent of Israeli settlements around East Jerusalem dividing it from the rest of the West Bank and its Palestinian population centres, and create a continuous Jewish population between Jerusalem and Ma'ale Adumim. It would also nearly bisect the West Bank jeopardizing the prospects of a contiguous Palestinian state. Palestinians describe the E1 plan as an effort to Judaize Jerusalem.
The international community considers Israeli settlements in the West Bank illegal under international law, but the Israeli government disputes this.