Have you ever seen the Smoke Signal Station? Today, I went to War Memorial of Korea.

Beetween many things, I liked Smoke Signal Station the most.

At Joseon period, Joseon people used Smoke Signal Station for telling the enemy's conditions.

We used fire in night, smoke in daytime.

If we put the fire on one Smoke Signal Station, it means it's normal condition, if we put the fire on 2, it means the enemy is preparing for war, 3 means the enemy is near the border, 4 means the enemy crossed the border, 5 means it's time to fight.

I think Smoke Signal Station is a creative invention on the Joseon Period. thank you