A difficult point that frustrated feudal lords (daimyo) and travelers for 250 years
When the 5 highways leading to Edo were opened, the starting of the checkpoints came from their positioning on each of those highways to enhance security. The checkpoint for Hakone was established in 1618, and with the initiation of the “sankin kotai” (alternate attendance) system in which the daimyo were duty-bound to spend a fixed period of time residing in Edo, the tightening of security became strict. Initially, the strictness applied to daimyo, but gradually this expanded to the townspeople which troubled people going back and forth through Hakone. The checkpoint was abolished in 1869 but it was completely restored in 2007. Mannequins of government officials of the time have been re-created inside the building but they are displayed without color since the details of the color of their clothing are not known.
A particularly strict part was “Irideppo ni Deonna”
One traffic policy during the Edo Era was the “Irideppo ni Deonna” (one gun in, one woman out). The term meant that for every gun entering Edo, one woman would leave Edo, a particularly careful tightening of security. This was restricted to the wives of daimyo who were forced to live in Edo as hostages when they first underwent the sankin kotai, but little by little, this policy also came to apply to trips involving all women. Old women, known as hitomi onna, would be checked and harassed for their hair, distinguishing marks and whether they were pregnant or not. Breaking through the checkpoint was considered to be a serious crime, and so instigators or conspirators would be given harsh penalties such as crucifixion. Going up the steps rising from behind the checkpoint will bring you to a 2-storey building. This is the Lookout which once guarded the highway in preparation for any break through the checkpoint, the surrounding area and Lake Ashi. Now, it’s popular as a viewing spot and on a clear day, you can see Mt. Fuji.