Descending from modernism, Brutalism is said to be a reaction against the nostalgia of the 1940s. Derived from the Swedish phrase nybrutalism, the term "New Brutalism" was first used by British architects Alison and Peter Smithson for their pioneering approach to design.

The style was further popularized in a 1955 essay by architectural critic Reyner Banham, who associated the movement with the French phrases beton brut ("raw concrete") and art brut ("raw art").

The style was partly foreshadowed by the modernist work of other architects such as French-Swiss Le Corbusier, Estonian-American Louis Kahn, German-American Mies van der Rohe, and Finnish Alvar Aalto.

Given the style's European roots, it's no surprise that many of the structures that appear on this Instagram account are from that continent.

One of Brutalism’s most famous critics is King Charles III of England, whose speeches and writings on architecture have criticized Brutalism, calling many of the structures "piles of concrete" and likening them to "a monstrous carbuncle."

And his arguments were valid. Brutalism's functionality made it the perfect fit for cash-strapped post-war Europe, seeking to rebuild urban centers for growing populations. It became the go-to choice for many low-cost housing projects and, as a result, in Western Europe, Brutalism became a symbol of poverty. In Eastern Europe this was compounded; elision between projects and the governments that commissioned them often precluded appreciation of Brutalism's merits.

"A lot of post-war developments were really badly designed and badly maintained housing estates," Peter Chadwick, the author of This Brutal World told CNN.

"Flats, many stories up, don't have direct access to outside space, so the 'outside' is on the ground level. There's these negative, redundant spaces around the building, which prompts anti-social behavior. Brutalism has suffered because of this."

Although the Brutalist movement was largely over by the late 1970s and early 1980s, it has experienced a resurgence of interest since about 2015.

Many of the defining aspects of the style have been softened in newer buildings, with concrete façades often being sandblasted to create a stone-like surface, covered in stucco, or composed of patterned, pre-cast elements. These features are also found in renovations of older Brutalist buildings, such as the redevelopment of Sheffield’s Park Hill in South Yorkshire, England.

However, its future remains cloudy. "Unfortunately it's a lot more expensive to preserve the buildings than to knock them down and build something else in their place," Chadwick explained.

"[Brutalism] is definitely having its moment, which is great. I just hope it continues, the interest and the preservation of buildings, before we lose any more."