Human waste left behind by climbers using sections of trails on Mount Fuji where there are no toilets have raised concerns about whether the mountain’s pristine scenery can be maintained, after the iconic volcano was last year added to UNESCO’s World Heritage site list, according to an NHK report.

The Shizuoka Prefectural Government realized after the mountain was closed last week to climbers for the year that human waste had been left in several locations, including some 900 meters from the fifth station on the trail known as the Subashiri route.

Toilets are located along the mountain’s trails except for between the fifth and sixth stations.

The lack of sufficient toilets was one of the reasons why the country in 2003 opted not to recommend Mount Fuji for the UNESCO listing despite the desire of citizens and officials.

Since then, the prefecture set up micro-organism treatment toilets. The latest waste problem was discovered after the prefecture distributed to claimbers portable, plastic bag-type toilets and asked them to keep the mountain clean in light of its world heritage listing, the report said.

The country was asked to submit a schedule for improving the situation to UNESCO by February 2016, it said.