The multi-storied manor houses and watchtowers of Han towered above the countryside. Some lords built watchtowers and hired private armies to protect their property. This tower is built over a pond as indicated by the fish, frogs and aquatic fowl in the round basin-like base. The corners of the balcony show soldiers with crossbows. Though invented during Warring States period (481-221 b.c.), crossbows were perfected during Han. Central to military control, the powerful weapon gave the Han an advantage against all enemies. In fact, the crossbow was a state secret protected by the death penalty.