An island where men have to strip naked and women are not allowed is one of the latest sites to be listed on Unesco’s World Heritage List.

The island of Okinoshima in Fukuoka, Japan joins 10 other new sites and two extensions on the list announced at the World Heritage Committee meeting in Krakow, Poland on July 9.

The sacred island of Okinoshima (closed to tourism), located 60km of the western coast of Kyushu has had ritual services performed there during the 4th to 9th centuries. They included prayers for the safety of seafarers. In the 17th century the Okitsu-Miya Shrine was built for similar prayers. Priests from Munakata Taisha, a group of Shinto shrines, reported The Guardian, are in principle permitted to travel to the island to worship at that shrine.

However every year, up to 200 men on May 27, can also visit the island to honour sailors who died in a battle at sea during the Russu-Japanese War of 1904-05.

Before they set foot on the island, they must undergo some old rituals including removing their clothes and cleansing themselves in the sea. When they return home they are not allowed to speak of what happened on the island. They are also not allowed to take back any souvenirs from the island.

Why women are banned from the island though is unclear.

A Hindu organisation in the United States, the Universal Society of Hinduism in a press statement accused Unesco of hypocrisy by approving the listing of Okinoshima.

“Unesco should not be in the business of rewarding the monuments/sites which refused to treat women with equality and respect they deserved. Women were entitled to equal rights and opportunities and this gender discrimination at the Island needed to end right now as it was highly inappropriate and out-of-line.” it said.

Gender Equality is listed as one of two global priorities in Unesco’s website.

Some of the other sites that were just listed included the Historic City of Yazd in Iran, Taputapuatea on Ra’iatea Island in the Pacific Ocean, the Caves and Ice Age Art in the Swabian Jura in Germany and the Assumption Cathedral and Monastery of the town-island of Sviyazhsk in Russia.