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. Rising to a height of 13.6 metres (45 ft) above the sea and extending some 427 metres (1,401 ft), with seventy columns, an intercolumniation of 6 metres (20 ft), and a width from column to wall of 8 metres (26 ft), the form, inspired by a Roman arcade, is said to be without parallel.