Are the cities of the future located in the ocean? Can AI Realize Floating Cities? Japan has unveiled an audacious plan: a floating city called Dogen City. AI makes a 50,000-resident city viable via Structural Safety (typhoon defense), Digital Twins (robotic maintenance), and Predictive Healthcare. As climate change accelerates, the world seeks innovative solutions. Japanese startup N-ARK has proposed a visionary design to tackle rising sea levels and climate risks. Key Features: Triple Structure: A 1.58 km-diameter ring comprising a habitable ring (tsunami-resistant barrier), undersea data centers (cooled by seawater), and a flexible floating architecture zone. Healthcare Hub: Positioned as a “Medical City at Sea,” integrating AI health monitoring, telemedicine, and undersea surgical facilities. Self-Sufficiency: Designed for full autonomy in food, water, and energy through seawater agriculture, desalination, and renewable power (solar, wind, and wave). Building "artificial land" requires $25B – $40B. Over a 20-year cycle, this is a "bankable" case for sovereign funds via medical tourism and data revenues.This matches prime real estate prices in NYC or London but includes climate immunity and AI-integrated living.