These makeshift communities are mesmerising and astounding feats of architecture

Three-car garages and big backyards are a common sight in the US, but they’re foreign in many other places.

Elsewhere, communities spring up by the people who build them, whether due to a lack of resources, political movement, or simply the will to survive after a natural disaster.

Not all of them are pretty, but design aesthetic isn’t always a consideration when you need a roof over your head.

Scroll down to see some of the most harrowing feats of construction around the world.

Kowloon Walled City, Hong Kong. Erected between 1950 and 1994 mostly by immigrants, the walled city was 119 times denser than New York City.

The packed region was essentially lawless. Dentists operated without licenses, as did food and textile manufacturers.

Living conditions were bleak. Devoid of sunlight, the inner workings were dank, dark, and impossibly confined.

Still, many experienced their formative years in the city. When it was torn down in 1994 to make room for a park, more than 33,000 peopled called Kowloon home.

Rio de Janeiro, Brazil. Scattered along the sides of the city's mountains are hundreds of densely packed favelas -- or shanty towns.

The first favelas were built by soldiers during the late 19th century. Since then, they have gained notoriety for their iconic look and strong ties to drug crime. More than a quarter of Brazilians live in these communities.

For both the Olympics and World Cup, police have 'pacified' many favelas, often curbing violence in order to accommodate the thousands of tourists staying in the city. Many favela residents see pacification as an invasion of their communities, however.

The 2011 occupation of New York's Zuccotti Park offered a non-hierarchical alternative to top-down capitalism.

After 60 days, however, New York City officials cleared the park -- taking much of the wind from Occupy's sails ...

...even if the message itself continues to live on.

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