city in Japan is having  problem with graffiti. However, it is not  usual type of graffiti with paint from spray cans being used to write on walls. It is graffiti in sand. Officials in  city of Tottori are asking tourists to refrain from writing messages and pictures in  sand of its giant sand dunes. The officials said  graffiti causes damage to the dunes and destroys  pleasure others get in looking at  sand. They said that more than 3,300 cases of 'sand graffiti' have occurred at  tourist hotspot in the last decade. The Mainichi newspaper said there were more than 200 cases reported last year. In January, two overseas tourists were ordered to erase  25-metre-long message that read: 'Happy Birthday Natalie'.
The Tottori Sand Dunes are famous throughout Japan for their natural beauty. They are  largest and longest sand dunes in  country and form part of  scenic geo-coastal park on  Sea of Japan coast. The biggest dune is 50 metres high. The dunes stretch for 16 kilometres along  coast. The local government wants to improve tourists' understanding of  importance of the dunes. It will set up more signs in English, Chinese and Korean asking people to respect  dunes. More and more tourists are visiting  site each year. A spokesman said: "We are concerned about whether  rules are fully understood, but we want to continue to protect views of  beautiful sand dunes."