S P O T ／ SPOT-223

Sarushima Island

猿島さるしま

Sarushima is an uninhabited island in Tokyo Bay off Yokosuka, the largest naturally forested island in the bay. Inhabited since the Jomon period, it gained strategic importance in the late Edo period when the shogunate built three coastal batteries in 1847 against the threat of foreign ships. When Commodore Perry's fleet arrived in 1853, his flagship anchored offshore and Perry reportedly nicknamed the island after himself. After the 1855 Ansei Edo Earthquake destroyed the batteries, the island was abandoned militarily until 1881, when the Imperial Japanese Army began constructing the Sarushima Battery as part of the Tokyo Bay Fortress. Completed in 1884 under engineer Captain Isao Uehara, who had studied fortification in France, the site features one of Japan's earliest examples of French-bond (Flemish-bond) brickwork, including a 90-meter brick tunnel that remains remarkably intact. The island was requisitioned by U.S. forces from 1947 to 1961, transferred to Yokosuka City in 1995, and designated a National Historic Site in 2015 as part of the Tokyo Bay Fortress Ruins. Today, a ten-minute ferry from Mikasa Pier brings visitors to a place where moss-cloaked masonry, vine-wrapped tunnels, and Tokyo Bay vistas evoke comparisons to Studio Ghibli's Castle in the Sky.