Okunoshima (Rabbit Island) 大久野島（うさぎ島）

Ōkunoshima is a small island in Japan's Seto Inland Sea, part of Takehara, Hiroshima Prefecture. The Imperial Japanese Army built a secret poison gas factory on the island in 1925 for chemical warfare during the Second Sino-Japanese War. After World War II, the island was redeveloped as a park, and domestic rabbits were released, leading to a current population in the thousands.

Source: en.wikipedia.org ↗, read 2026-09-10