When Japan endured an earthquake in 2019, a tsunami warning was issued as well. A 6.8 magnitude earthquake did hit, but the tsunami warning was eventually lifted. As citizens of a coastal country, the Japanese frequently face both earthquakes and tsunamis. A tsunami is a series of high ocean waves caused by an earthquake, an underwater landslide, a volcanic eruption, or an asteroid. Tsunamis can travel from twenty to thirty miles per hour, and their waves can reach a height of anywhere from ten feet to one hundred feet high. If Japan is especially well prepared for tsunamis, it’s partially because preparing for tsunamis is a well documented part of the country’s history.

Fifteen thousand eight hundred ninety-four people died in the tsunami of 2011. Another one thousand five hundred are still missing. The tsunami caused a meltdown at Fukishima’s nuclear power plant. The Japanese government has responded to the tsunami by building seawalls. The forty-one foot high seawalls, which are designed to prevent or delay the tsunamis from flooding vulnerable, inhabited areas, stretch two hundred forty-five miles along the coast. The seawalls aren’t universally popular. Some inhabitants worry that they will disrupt natural water flow, decrease tourism, or divert funding that could be allocated to more urgent infrastructure projects. In addition, the building project is costly. As of 2018, the Japanese government had spent over twelve billion dollars on the seawalls. Though this contemporary solution might be effective, past inhabitants of high risk tsunami areas left a record of their simpler, cheaper solution. Until the mid twentieth century, people wouldn’t build homes below certain points, in order to stay above the reach of a potential tsunami.

In some cities, inhabitants still honor their ancestors’ warnings. Tsunami stones are stones warning people not to build above the point they mark. They can be anywhere from two to ten feet tall. All of the stones, which are most commonly found on Japan’s northeastern coast, bear messages that have been carved into the stone for countless generations to find them. Some bear the death tolls from past tsunamis. Some bear direct messages for any passerby who is wise enough to listen. A tsunami stone is Kesennuma, reads: “Always be prepared for unexpected tsunamis. Choose life over your possessions and valuables.” Perhaps Japan’s most famous tsunami stone is the one in Aneyoshi. Aneyoshi has survived two tsunamis, one in 1896 and one in 1933. A four foot tall tsunami stone was erected after the 1933 earthquake. It reads, “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.” There were four survivors of the 1933 Aneyoshi earthquake, and all of them moved upland.

Some areas are also given names that serve as warnings. Valley of the Survivors and Wave’s Edge, for example are on safe, high ground, while Octopus Ground is named after the sea life beached by the tsunami. Fumihiko Imamura, a professor of disaster planning who works at Tohoko University, says these historical reminders are necessary, because survivors usually only successfully pass down their stories for three generations. Afterwards, subsequent generations forget the hardships their ancestors have endured, unless those ancestors leave behind a record. The tsunami stones are certainly valuable historical records. Unfortunately, some stones bear messages that cannot be read, because the stones have been worn by tsunami waves.