Japan is planning one of the world’s most ambitious infrastructure projects—Ocean Spiral, a futuristic underwater city powered by the temperature gradients in ocean water. Designed by Shimizu Corporation, this conceptual city will include a floating sphere above the surface and a spiral structure plunging 4,000 meters into the deep sea, allowing humans to live, work, and even mine ocean-floor resources. Powered by Nature: It will harness Ocean Thermal Energy Conversion (OTEC) technology—an innovative method that generates electricity from the temperature difference between warm surface water and cold deep water. The City’s Promise: Fully self-sustaining energy Food production and seawater desalination Deep-sea exploration and rare metal extraction Disaster-resilient infrastructure If brought to life, Ocean Spiral won’t just be a city—it’ll be a blueprint for sustainable living in an age of climate and land challenges. #OceanSpiral #JapanInnovation #FutureCities #UnderwaterCity