The 9th of November 2009 is the 20th anniversary of the fall of the Berlin wall.
It was one of the most important events in recent European history and paved the way for the reunification of East and West Germany after more than 40 years of division.
From the Berlin wall to the Belfast Wall, it seems barriers and borders are constantly going up and coming down.
Skyscanner introduces the longest, tallest and stickiest walls around the world.
Berlin Wall, Germany
Built in 1961, the 87 mile (140km) long Berlin Wall encircled West Berlin, separating it from East Germany and came to symbolise the Iron Curtain that divided Western Europe from the Eastern Bloc. Berliners will celebrate 20 years since the fall with the “Festival of Freedom” during which thousands of 2.5m tall dominos will be set up along the former course of the wall and toppled to symbolise its destruction. Find cheap flights to Berlin
Great Wall of China
Surely the most famous wall of all, China’s monstrous construction stretches almost 9000km (6000miles) across the north of the country. Originally built to protect the Chinese Empire from the nomadic Xiongnu attackers, large parts of the wall have fallen into disrepair. However, huge sections have been preserved and it’s one of China’s most iconic attractions. Find cheap flights to Beijing
Walls of Constantinople, Istanbul, Turkey
This series of defensive stone walls were built to surround the (then) city of Constantinople. The impressive gates are castle-like in their mighty construction, and protected the city from attack from both sea and land. The walls proved their worth, saving the city and the Byzantine Empire from several sieges, although they proved less resilient to the advent of gunpowder. Find cheap flights to Istanbul
Western Sahara wall, Morocco/Western Sahara
Started in 1980, this 2700km sand and stone construction runs through Western Sahara and the south east of Morocco and was built to separate the Moroccan controlled areas from the Polisario controlled areas. Standing at around 3m in height, much of the wall runs through uninhabited territory and is dotted with fences, landmines and artillery posts. The wall is part of an ongoing dispute between Western Saharans who want independence from Morocco. Find cheap flights to Marrakech
Western Wall, Jerusalem, Israel
Also known as the Wailing Wall, much of this construction is hidden behind and below other buildings built along its length. However, there is a 57m exposed section which is an extremely important landmark, and has become a place of pilgrimage for Jews. Its importance lies in the fact that the Western Wall is the only remnant of the Holy Temple, and it’s the closest accessible site to the most sacred spot in Judaism. Find cheap flights to Tel Aviv
Hadrian’s Wall, England
This 117km stone and turf fortification was built by the Roman Empire across the entire width of northern England in an attempt to keep those pesky northern barbarians out. Now a UNESCO World heritage site, much of the wall still exists and the Hadrian’s Wall Path is popular with hikers and walkers. Find cheap flights to England
Belfast Peace Line, Belfast, Northern Ireland
This series of barriers and walls were built to separate Catholic and Protestant neighbourhoods in Belfast. Constructed of iron, brick and steel, they stand at over 20 feet high, stretch for several miles and are dotted at intervals with manned gates. Parts of the Belfast Peace lines have become tourist locations but the future of the barriers is under discussion, with the possibility of their deconstruction a hot topic. Find cheap flights to Belfast
Israeli West Bank barrier, West Bank
Currently the most controversial wall in the world, the Israeli West Bank barrier is a network of fences, trenches and concrete walls up to 8m high currently being constructed by the Israeli government to separate the Israeli and Palestinian populations in the West Bank. The barrier is an ongoing source of dispute and unrest between the two peoples. Find cheap flights to Tel Aviv
Walls of Dubrovnik, Croatia
This series of stone walls that surround the city state of Dubrovnik have protected it from attach since the 7th century and have been considered amongst the greatest fortification systems of the medieval period – having never been breached by a hostile army. The old city of Dubrovknik is now a UNESCO World Heritage site, and much of the city walls have been preserved and remain a popular tourist attraction today. Find cheap flights to Dubrovnik
Gum Wall, Seattle, USA
Not all walls divide people; some stick them together. Seattle’s Gum Wall was once just an average brick wall, but it’s now blanketed in chewing gum and has become one of the city’s stickiest sights. The tradition of placing used chewing gum on the wall was started by punters queuing for a nearby theatre; now the wall is plastered in gum several inches thick. According to the Seattle Times, it has even become a popular place for more quirky couples to take their wedding photographs. Find cheap flights to Seattle (image: Mademan.com)