The last of Northern Ireland's "peace wall" was put up in the grounds of a school in 2008
On the 20th anniversary of the fall of the Berlin Wall, BBC Mundo looks at barriers which are still standing - or have gone up since - around the world.
Northern Ireland's so-called "peace lines" began to appear 40 years ago in Belfast, initially as a temporary measure but they continued to grow.
They are a series of barriers that separate Catholic and Protestant communities varying in size from a few hundred metres, to 5km (3 miles) in length.
Despite the fact that they have now become a tourist attraction, they are testimony to the very recent history of violence between Catholics and Protestants in the UK province of Northern Ireland.
The first of these walls was erected in 1969, following riots and burning houses in the west of Belfast.
Over the years the wall, which separates the Shankill and Falls roads, rose to a height of 6m (19ft).
The last of the walls was built as recently as last year, in the grounds of a primary school in the north of Belfast, following a period in which tensions were escalating between the two communities.