A Japanese has a graffiti . It is graffiti in . The city wants to stop writing on the city's sand dunes. It damages the dunes and stops enjoying them. There were more than 3,300 of 'sand graffiti' in the ten years. In January, two tourists wrote a 25-metre- birthday .
The Tottori dunes are in Japan. They are Japan's and longest dunes. The biggest is 50 metres . They are 16 kilometres long. They are on the of Japan . There are now to ask people to follow the . The city said: "We want to continue to protect of the sand dunes."
