Arayashiki Shell Mound

The Arayashiki Shell Mound is an archaeological site in Wakaba ward shaped like a horseshoe and sits at about 31 meters in elevation. The mound measures roughly 150 meters from north to south and 160 meters from east to west.

The site was discovered in 1872 when workers found it during lime mining operations. The remains date to the middle Jomon period, roughly 5500 to 3500 years ago.

The mound reveals what people ate thousands of years ago, with shells from Tokyo Bay species like clams and cockles scattered throughout. These remains show us the daily food sources and eating patterns of the ancient inhabitants who lived here.

The site can be reached on foot from nearby bus stops or transport hubs. The location is accessible and open to visitors without difficulty.

When plans threatened to destroy the mound in 1964, engineers built a tunnel underneath it for a road extension instead. This clever solution saved the site from disappearing entirely.

GPS coordinates: 35.62231,140.14495

Latest update: December 14, 2025 18:01