Sejong (from 2012) is South Korea's purpose-built administrative capital, planned to relieve Seoul by relocating government ministries into a decentralized, ring-shaped, green city without a single dominant centre, organized around a looping transit spine.
Significance
Sejong is a major contemporary experiment in administrative decentralization and the 'centerless' city, testing whether relocating government can rebalance an over-concentrated national capital region.