Sea Fortress, completed in 1989, is a distinctive residential facility designed by Dang and Aoshima Architectural Design Office. Located in Oki, Saiiki District, Hiroshima Prefecture, this architectural gem masterfully integrates with its coastal environment. The building exemplifies innovative design principles that harmonize modern construction with the natural landscape. Its fortress-like form creates a striking visual presence against the maritime backdrop. For architecture enthusiasts, Sea Fortress represents a compelling example of late twentieth-century Japanese architecture that prioritizes both aesthetic boldness and functional accommodation for guests.