A Brief Architectural History of the Domination of the Circle in “Ideal” Urban Plans

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In 360 BC, Plato wrote Critias, a mythological account of an island city situated just outside the straits of Gibraltar, the city of Atlantis. For Plato, this myth was an experiment, an attempt to explore the makings of an ideal city socially, culturally as well as architecturally. He described the urban plan of Atlantis as a series of concentric circles alternating between land and sea (two rings of land and three of sea), circling a small hill upon which the shrine and the palace of Poseidon and his wife Cleito were situated. The circular layout was then divided into ten, identical territories, where a series of canals, filled with seawater, sliced through the land. Each ring is designated to specific social clusters and activities. The first, and smallest one, was reserved for the Atlantean aristocrats as well as an array of temples for multiple gods. The second ring was partly a hippodrome, a course for horse racing, housed barracks for the personal guard and included dockyards full of triremes for trading. Finally, a circular wall made of stone enclosed the whole city.

It is no coincidence that, in Critias, the philosopher attributes the creation of Atlantis to a god, Poseidon. Through this narrative, Plato underscores that the ideal city, shaped as a perfect circle, could not have been achieved by human hands alone. This divine origin serves to emphasize the unattainable perfection of such a design, aligning with Plato’s broader philosophical exploration of the “ideal” city. He views the circle as a symbol of total symmetry and divinity, crafting a mythical narrative where he obsesses over the way the particular shape communicates absolute harmony and unity — a philosophical metaphor for the divine.

Even though the circle as a shape carries the mathematical purity and form that charms architects, designers and urban planners, I believe that the story of Atlantis greatly influenced the idea of what an ideal city should look like and served as a template for many utopian city concepts. Still, apart from the circle’s symbolic nature are there any other reasons that this shape is considered ideal for city planning? In truth, the practicality of the circle still hides ideological connotations. For instance, by placing specific functions (such as temples or administrative buildings) at the center, imply a sense of societal hierarchy and power, while concentric arrangements also provide practical defense — essential for ancient historical cities.

The Round City of Baghdad build in Iraq, in 762 CE or Madinat-al-Salam (the City of Peace) was considered as one of the most advanced cities in the world. The city’s design is comprised of three perfectly round walls, interrupted by four gates. The two wider rings were home to a series of residential and commercial structures, while in the center lay the palace, the mosque, the guards headquarter as well as the famous library known as the House of Wisdom.

Palmanova is a town in Italy that was originally planned and built in 1593 as a military outpost, part of the Venetian Republic’s defenses against the Ottoman Empire. Its plan is a nine-pointed, circular star surrounded by a bastion wall, with three gates placed in the gap between every three points. At the center, a hexagonal piazza was designed as a parade ground, while the gap between the wall and the piazza was used for the homes of the Venetian troops, the civilians and the mercenaries, who were positioned closer to the outer wall. Even though the town was intended primarily for military defense, the goal was to create a utopian, self-sustaining model in which merchants, craftsman and farmers could live in social harmony.

Garden City, 1898 is probably the most well-known circular urban plan of the modern world. It was designed by English planner Ebenezer Howard in order to respond to the challenges brought by the industrial revolution, such as pollution, irregular settlements and overcrowded cities. He shifted his attention to the English countryside, proposing a plan made of concentric circles that was separated in autonomous, egalitarian districts that were developed into zones for commerce, services, housing, agriculture and industries at the outer borders, while public buildings, cultural institutions and a hospital were situated within the inner part of the plan. These settlements were then surrounded not by walls but rather green zones, in an attempt to limit any uncontrolled urban expansion.

Nowadays, urban planning has somewhat diverted from the “perfect circle.” There have been some contemporary works such as Le Corbusier’s plan for Chandigarh in the 1950s or Brasília’s layout by Lúcio Costa and Oscar Niemeyer in 1960, which incorporate circular or radial components. However, the circle as a shape remains mostly in the realm of a mythical concept, a Renaissance experiment, or a futuristic vision, being too rigid and austere to deal with the organic growth of existing urban fabrics. Still, all these previous examples have unlocked concepts and strategies that may be key in tackling contemporary urban challenges. Concepts like the fifteen-minute city, where all essential services are within a short walk or bike ride, align well with circular layouts that prioritize centrality and connectivity. In parallel, all “ideal” cities embrace examples of renewable energy, autonomy and resource-efficient designs, where closed-loop system echo the form’s ancient connotations of renewal and symmetry.

What is perhaps less widely known is that, in Plato’s myth, Atlantis was ultimately destroyed by the gods’ wrath for succumbing to greed and hubris — its perfection became its downfall. Similarly, architects and urban planners who wield the circle as a symbol of ultimate control risk losing sight of its deeper essence. The power of the circle lies not in its rigid geometry, but in the principles it represents: cultivating systems that foster resilience, equity and sustainability as well as the ability to unite rather than divide.

The latest edition of “Architizer: The World’s Best Architecture” — a stunning, hardbound book celebrating the most inspiring contemporary architecture from around the globe — is now available. Order your copy today.  

Featured Image: Ebenezer Howard, Diagram No.3 (Howard, Ebenezer, To-morrow.), marked as public domain, more details on Wikimedia Commons