Damn, that's cool history, thanks for sharing!

I found this in a similar vein not too long ago: https://en.wikipedia.org/wiki/Tsunami_stone

A tsunami stone is a type of stone monument found in Japan that warns people to move upwards after a large earthquake to avoid a potential tsunami. 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. 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."