View of Hakone-machi, c. 1910. The ladder and attached bell constitute the traditional Japanese fire “alarm” system.

“Its strategic position was an exceedingly strong one, for from the west of Idzu and the Hakone hills its western frontiers were ringed with a mountain rampart which made an invasion a really formidable affair to those who should undertake it. The main approaches were then, as now, by the Nakasendo and the Tokaido – only the Tokaido at that date ran around the north of the Hakone Lake instead of to the south of it at present – and the provisioning of any large assailing force, unless supported by a fleet, would have been a matter of great difficulty.”

– A History of Japan, by James Murdoch & Isoh Yamagata, 1903

From the wiki: “After the start of the Edo period Hakone-juku (also known as Hakone-machi) was a post station on the Tōkaidō highway connecting Edo with Kyoto, established in 1618 in a small area between Hakone Pass (on Mount Hakone) and the Hakone Checkpoint; a major barrier and official checkpoint on the route which formed the southern border of the Kantō region. Under the Tokugawa shogunate, all travelers entering and leaving Edo along the Tōkaidō were stopped here by officials. Their travel permits and baggage were examined to enforce Tokugawa laws that restricted the travel of women and weapons.”