Photo/IllutrationThe ruins of an artillery battery, observation tower and other structures remain at the No. 2 Sea Fort off the coast of Futtsu, Chiba Prefecture, on July 10. (Minao Ota)

YOKOSUKA, Kanagawa Prefecture--Five companies are offering trial tours to the ruins of an artificial island fortress that government officials hope will eventually become a tourist hotspot in Tokyo Bay.

The No. 2 Sea Fort off the coast of Futtsu, Chiba Prefecture, was completed in 1914 to defend the capital from world powers. The fortress, which is about 41,000 square kilometers, can reached by boat from Yokosuka.

Complete with an artillery battery, the fort was also equipped with an anti-aircraft cannon during World War II.

The fortress was demilitarized on Aug. 30, 1945, when British troops landed on the island. The artillery battery and other facilities were apparently destroyed at the time, but parts of the ruins remain on the island, located about 2.5 kilometers from Futtsu point.

The fort had been off-limits to the general public. However, the Ministry of Land, Infrastructure, Transport and Tourism decided to allow landings on the island on a trial basis to explore ways to use the fortress as a tourism resource.

The trial tours will be offered through October.

Tour participants can look not only at the ruins, but they can also get close-up views of large vessels traveling through the Uraga Channel.

Before the off-limits restriction was lifted, a tour was planned in July to view the fort from a cruise ship. About 3,600 people applied for the 50 available spots.

The island has promise as a tourist destination because cruise tours of naval ports and sightseeing boats traveling through the nearby Sarushima island route are also popular in Yokosuka.

The five companies’ tours are different in terms of content, fees and availability. For example, one tour includes a bus trip that leaves and returns to Tokyo, while another is bundled with a cruise ship tour to naval bases.

The land ministry and other parties plan to offer regular tours after reviewing issues from the trial run and determining if modifications and other measures are necessary.