As the world looks to create more resilient coastal communities, some project teams are reimagining what and where a city can be. One vision: an ultra-modern, uber-ecofriendly, endlessly adaptable extension of the South Korean port city Busan—built directly atop the water. Now Busan’s government leaders are collaborating with unhabitat, sustainable technology firm oceanixcity, and a slew of high-profile partners to “scale this audacious idea.” The plan calls for a trio of linked floating platforms—one for housing, one for public spaces, and one for R&D—connected to the mainland by bridges. And these aren’t just any platforms. The team used hydrodynamic analysis to model how they would react to wave and wind scenarios, iterating the designs to minimize movement while ensuring the structures could withstand the most brutal of storms. If successful, Oceanix Busan—initially designed for 12,000 residents—could expand into a honeycomb system supporting around 100,000 people. “We develop...