The Digital Press

Tokyo has built a massive underground flood defense system called the Metropolitan Area Outer Underground Discharge Channel to protect the city from flooding caused by typhoons and heavy rains.

Why it matters: The $2 billion system can divert and pump out massive floodwaters, reducing flood risk in a highly urbanized city.

The big picture: Climate change and shifting rainfall patterns challenge Tokyo’s infrastructure designed for historic rain levels.

The stakes: Without upgrades, severe floods could impact 2.5 million people and devastate Tokyo’s low-lying areas.

Commenters say: Visitors are awed by the scale and engineering, noting its massive pillars and powerful pumps, while some highlight the difficulty of public access.