Koajiro Forest surrounding the Riviera Seabornia Marina, the southernmost tip of the Miura Peninsula,
It is a place where forests, wetlands, tidal flats and the sea are left in a row, and rare creatures such as Acategani form a diverse ecosystem.
In the Riviera, including Kanagawa Prefecture and Miura City,
In cooperation with the Kanagawa Trust Midori Foundation and the NPO Koajiro Outdoor Activities Coordination Council,
We are striving to preserve the richest natural environment and animals and plants in the Kanto region.

Riviera Initiatives

Koajiro Forest, where one basin is left untouched and completely preserved.
The area is about 70ha and covers 15 Tokyo Domes.
Under the guidance of the NPO Koajiro Outdoor Activities Coordination Council, the Riviera regularly conducts activities to protect virgin forests and tidal flats.
Including "improvement of river environment", in which river water flows from the headwater to the estuary without destroying the natural ecosystem,
We are focusing on “cutting sasa and controlling exotic plants” in connection with wetland restoration work.

Forest where Acategani lives

An unusual crab, Acategani that lives in the forest. On a full moon in the summer, on the tide night, mother crabs rush to the shore and release stomach larvae to the sea. Akagani can only be seen in Koajiro forest, where it can only live in places where beautiful forests and the sea coexist.

River where fireflies returned

Fireflies spend their larval life underwater and cannot live without a clean river all year round. The number of fireflies has also increased in Koajiro Forest due to river and wetland conservation activities. The forest where countless lights dance at night is very fantastic. Firefly observation sessions, which are held from the end of May every year, are also popular.


Mr. Yuji Kishi

Professor Emeritus of Keio University

"Koajiro no Mori" is about 70ha and 15 Tokyo Dome. It is "the only place in the Kanto region that can retain the entire ecosystem of the basin", and more than 2000 species of organisms have been confirmed. In order to protect this precious environment, it is important to frequent care with human hands. Trees are thinned so that they do not overgrow, and various insects inhabit by keeping the diversity of plants. Adjusting the flow of the river also widens the wetlands, increasing the variety of aquatic insects and attracting birds that feed on them. In this way, human beings are involved in nature, maintaining an appropriate natural environment and maintaining biodiversity. The Riviera also collaborates with NPOs to conduct regular maintenance activities by staff. In fact, wild fireflies returned in Koajiro. I hope that we will continue to walk with our hands so that people and nature can coexist.

Yuji Kishi / Representative Director, Koamidai Outdoor Activity Coordination Council Professor Emeritus of Keio University. Specializes in evolutionary ecology. Promote theory and practice related to urban regeneration of basin thinking in Koajiro and Tsurumi River basins. He has authored many books, including "Gaze to Nature" and "How to Create a Watershed Map".