A section of the biggest peace line� of West Belfast in Waterville Street, which was reinforced with concrete and extended with a fence on the top in 2008. Belfast, Northern Ireland, September 2008. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

A section of the biggest peace line of West Belfast at the crossing of First Street and North Howard Street which was reinforced with concrete and built higher in 2008. It separates a Catholic and a Protestant neighbourhood. Northern Ireland, September 2008. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

The very end of the Mexico-U.S. border running into the Pacific Ocean in Tijuana, Mexico. November 2008. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

A fence and watchbooth in the Spanish enclave of Melilla separating it from Morocco. The Mediterranean Sea is in the background. The fence was erected over the last decade to prevent immigration from Africa to the European Union. The enclave still has a big presence of Spanish soldiers here seen during training while coordinating with the Guardia Civil, which is in charge of guarding the border. March 2009. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

Observation post of the Korean army in the demilitarized zone between North Korea and South Korea. The U.S. Army also controls this part of the zone as part of a UN force. Panmunjom, Paju, Repubulic of Korea. September 2009. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

The illegal Israeli settlement of Pisgat Zeev in the Westbank seen from the Palestinian refugee camp of Shuafat in the outskirts of Jerusalem. Though the separation wall divides the inhabitants of these communities they both hold Jerusalem identity cards. The graffiti is the work of Palestinain artists from Jerusalem. People from around the world could contact them and get a quote written on the wall. Occupied Palestinian territories, November 2009. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

Walls marking the Turkish side of the demarcation line between Turks and Greece in the center of Nicosia, Cyprus. October 2010. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

Wreaths for the people who were killed crossing the Berlin Wall lay next to the memorial in Bernauer Strasse on the 50th anniversary of the wall's construction on August 13, 1961. Berlin, Germany, August 2011. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

A wall running through Shiite Sadr City in Baghdad. The wall was erected by the U.S. Army to protect an area from attack of the Mehdi Army, a Shiite militia following Muqtada al-Sadr, a Shiite cleric in the rank of a Sayyid. The wall is still in place and heavily guarded by the Iraqi army but inhabitants hit a number of holes in it or removed slabs. Iraq, January 2012. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.

Construction of the border fence between the U.S. and Mexico between Naco and Douglas, Arizona. April 2008. Photo: From Confrontier by Kai Wiedenhöfer published by Steidl.