What are the two oldest sand tables in China?

White rice piles and military sand tables.

The earliest recorded sand table in the history of China was in the Eastern Han Dynasty. "Once"? Ma Yuan Biography records that in the eighth year of Jianwu in the Eastern Han Dynasty, Xiao Wei, the local leader of Longxi, set out to crusade against Gongsun Shu, Sichuan, and enlisted troops to rebel against the imperial court. Emperor Guangwu Liu Xiu wanted to send troops to conquer, so he called the famous Ma Yuan to discuss the invasion strategy. Ma Yuan is very familiar with the geographical environment in Longxi. Seeing Emperor Guangwu's inquiry, he piled rice into a model similar to the actual terrain in Longxi area, and used the model to elaborate the enemy's situation in detail. Emperor Guangwu of Han Dynasty praised this particular image mode. This is the earliest sand table in China.

In ancient times, according to the needs of war, people used sand, small red flags, small houses, etc. to faithfully show the ups and downs of roads, bridges, rivers and terrain within the scope of combat, and vividly show the marching route and general plan.