Located on the Sekihoku Main Line in Hokkaido, the Jomon Tunnel is infamous for its gruesome history as a “human pillar” (hitobashira) site, where the remains of brutally exploited laborers were sealed directly into the tunnel walls. During repairs following a 1968 earthquake, workers discovered skeletons standing upright within the concrete, confirming decades of rumors about the “tako” laborers who died from exhaustion, malnutrition, and beri-beri during its 1914 construction. Paranormal reports are frequent and vivid, with train conductors and passengers claiming to see blood-covered ghosts wandering the tracks or hearing disembodied screams echoing through the 507-meter passage. Despite the chilling discovery of over 100 sets of human remains in and around the site, the tunnel remains a vital, operational part of Japan’s rail network in 2026, though it is marked by a somber memorial monument dedicated to the victims.