The Toi gold mine (土肥鉱山, also 土肥金山, Toi kinzan) was an important gold mine during the Edo period in Japan, located within what is now part of the city of Izu, Shizuoka Prefecture in the middle of the Izu Peninsula.

[1] The gold mine was operated on a large scale from the time of Tokugawa Ieyasu in the late 16th century.

[2] Workers were killed because of the exhausting conditions due to seeping hot springs and poor oxygen content of air, leading to the installation of water pumps and ventilators at numerous intervals.

The galleries of the mine total about 100 kilometers in length, over a surface of 37 hectares, and go as deep as 180 meters below sea level.

The museum received some fame for housing the world's largest gold bar, weighing 250 kg,[5][6] and representing a value of about $14.5 million in September 2022.