City walls

fortification used to protect an area from potential aggressors

city walls of Constantinople (modern Istanbul, Turkey)

walls that surround the Old City of Jerusalem

fortress in the city of Diyarbakır, Turkey

historic wall built around the city of Tallinn, Estonia

series of walls surrounding the old city of Nicosia, Cyprus

fortress in Azerbaijan

historic district in San Juan, Puerto Rico

wall built to the north of Babylon

historic moat in Nigeria

historic wall built around the city of Vilnius, Lithuania

building style

fortified gate, leading directly from a castle or town wall directly on to a quay, riverside or harbour

cultural heritage monument of Albania

city walls in Lubin, Lower Silesian Voivodeship, Poland

national monument of Nigeria in Kano

1470s-1860s in the now-Russian town

Series of fortifications surrounding the center of Basel, Switzerland

thumb|upright=1.75|Painting of the Linienwall fortification (by August Stefan Kronstein) The Linienwall was the outer line of the fortifications for the city of Vienna, Austria, that lay between the city's suburbs and outlying villages. Constructed in 1704, it was razed in 1894 to make way for the Vienna Beltway.

Series of historic walls built around the city of Amsterdam, Netherlands

archaeological site in Israel

fortification for a bridge

city wall

fortified wall which once encircled the old city of Riyadh

alt=Helen walking along a city walls, alone: two women stand in the background, looking down over the wall |thumb|Helen on the Walls of Troy (1865) by Frederic Leighton