The Kii Channel is a vital maritime gateway connecting Japan's Inland Sea to the Pacific.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Separating Shikoku from the Kii Peninsula on Honshu, the Kii Channel serves as a critical aquatic bridge. Known historically by various names, this strait is more than just a geographical divider; it is a complex intersection of national parks, regional prefectures, and modern energy infrastructure powering the Japanese islands.

The Kii Channel, also referred to as the Kii Strait, acts as a primary maritime conduit linking the Inland Sea with the vast Pacific Ocean. Geographically, it sits between the island of Shikoku and the Kii Peninsula on Honshu. Its name is derived from Kii Province, a historical administrative division that once occupied the peninsula. During the 19th century, Western cartographers occasionally identified this specific waterway as the Linschoten Strait, reflecting its significance in early maritime navigation records.

The surrounding geography is defined by three distinct regions: Tokushima Prefecture on Shikoku, Wakayama Prefecture on Honshu, and the southern coastline of Awaji Island, which belongs to Hyogo Prefecture. The channel's connectivity is intricate, linking to Osaka Bay through the Kitan Strait and to the eastern section of the Inland Sea, known as Harima Nada, via the Naruto Strait. A portion of this channel is protected under the designation of Setonaikai National Park, highlighting its ecological and cultural value.

Beyond its natural and historical importance, the channel plays a role in modern utility infrastructure. It hosts the Kii Channel HVDC system, a submarine high-voltage direct current transmission network. This system demonstrates how the strait serves as a strategic corridor for essential energy distribution between Japan's major islands. By bridging these landmasses, the channel remains a vital, multifunctional artery that supports both the environmental preservation of the national park and the industrial requirements of the surrounding prefectures.

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