A tsunami stone is a stone monument that warns people to move upwards after a large earthquake to avoid a potential tsunami.^[2] They are placed all around the coasts of Japan. Some simply provide this warning, while others list death tolls, are placed near mass graves or say where homes should be built. They have a flat face and some are as high as 3.0 metres (10 ft) tall. Some are over 600 years old and some have aged so much that the characters written on them have disappeared. Most were placed in about 1896 after an earthquake and two tsunamis that year caused about 22,000 deaths.^[3] The tsunami stone in Aneyoshi says: "High dwellings are the peace and harmony of our descendants. ... Remember the calamity of the great tsunamis. Do not build any homes below this point."^[2]

The stones help remind people, as according to Tohoku University professor Fumihiko Imamura, "It takes about three generations for people to forget. Those that experience the disaster themselves pass it to their children and their grandchildren, but then the memory fades."^[2] As some coastal towns have modernised and have built seawalls, some citizens have started ignoring the stones as they have started believing that the sea walls will protect them.^[4] Japan lies on the Ring of Fire, which experiences about 80 per cent of the world's major earthquakes and tsunamis. In Japan, about 1,500 earthquakes strong enough to be felt by humans occur every year, with about 18 per cent of the world's earthquakes occurring within the country or in close proximity to it.^[5]

The stones are viewed as outdated by many Japanese people. After the 2011 Tōhoku earthquake and tsunami, it was suggested that some tsunami-ruined buildings be preserved to serve as warnings. This is similar to the Hiroshima Peace Memorial which was preserved after the bombing of Hiroshima in 1945.^[3]

• Natural disasters in Japan
• Tsunami Warning (Japan)