The North Breakwater Dome (北防波堤ドーム, kita bōhatei dōmu) is a long arched "semi-domical" structure in the port area of Wakkanai, Hokkaidō, Japan.

[1][2] In accordance with the 1905 Treaty of Portsmouth, South Sakhalin was incorporated into the Empire of Japan and governed as Karafuto Prefecture.

Initial plans for the north breakwater were for its parapet to rise to a height of 5.5 metres (18 ft), but this was considered insufficient to withstand winter storms.

A revised design was formulated by twenty-six year-old Tsuchiya Minoru (土谷実), a graduate of the Department of Civil Engineering at Hokkaidō Imperial University.

By the late 1960s the concrete of the Dome was deteriorating, with the volumetric expansion of the corroding steel used for reinforcement, after many cycles of freezing and thawing, and the action of salts.