Genbudo Museum & Park

Genbudo Museum was newly reopened in the spring of 2018 after undergoing extensive renovations to house its collection of rare minerals and precious stones as well as newly added fossils that include a t-rex, pterosaur, and Asian elephant.
Located directly out in front of the museum is the natural national monument Genbudo Caves, also a part of the San’in Kaigan UNESCO Global Geopark.

Genbudo Museum is located at the entrance of Genbudo Park, a designated national natural treasure. On the first floor is a weaving workshop where guests can learn about Toyooka’s traditional art of weaving that has a 2,000-year history and about its connection to the local people. As one wanders the first floor they will also find themselves face to face with an Asian elephant fossil, ancient animals which once roamed the San’in Kaigan Geopark.

On the second floor there are exhibits covering beautiful and fascinating minerals and rocks as well as fossils including that of a t-rex. See if you can find the glowing and musical rocks on display.

At the restaurant seasonal items made with local ingredients are on the menu, and guests can enjoy a cool drink on a hot day or a warm drink on a cold day’s visit. The outdoor terrace offers a beautiful panoramic view over the Maruyama River and surrounding mountains. Go to the souvenir shop to find Toyooka bags, sweets, and more.

Home to the five beautiful basalt Genbudo Caves with over 1.6 million years of geological history, Genbudo Park was designated in 1931 as a National Natural Monument by the Japanese Government due to their significant role in the discovery of reverse magnetization, and the impressive caves are also part of the San’in Kaigan UNESCO Global Geopark, making it a perfect educational outdoor trip for visitors to the area.

Genbudo, Japanese for Basalt Cave and can also be interpreted as the Black Tortoise Cave, consists of 5 caves made of columnar joints that formed over 1.6 million years ago after the magma from a volcanic eruption cooled, contracted, and formed vertical cracks. These curvaceous columns have a distinctive polygonal shape and a honeycomb pattern. The five caves are each named after four Chinese mythological creatures Genbu (Black Tortoise), Seiryu (Azure Dragon), Byakko (White Tiger) and Suzaku (Phoenix). Two caves are named after the Phoenix but are either North Phoenix or South Phoenix.

Before becoming a park and museum for the public to enjoy, the Genbudo Caves were utilized as a quarry during the Edo Period (1603~1867), resulting in the recessed areas of the cave that are still viewable to this day. Locals discovered that the rocks could easily be used for building materials, and visitors can still see these basalt rocks just about everywhere during one’s visit to the area, including in the park’s walkways.

The basalt rocks also hold scientific and historical importance. In 1926, the Japanese geophysicist Motonori Matuyama was the first to surmise that the Earth’s magnetic field had undergone reversals in the past, a theory made here when he discovered that the polar magnetic alignment of this basalt is the opposite of the Earth’s current magnetic polarity. Evidence was found in Genbudo that sometime during the formation of this basalt the Earth had experienced a reverse of magnetic polarity.