Maimaizu-ido (まいまいず井戸, lit.'snail well') is an ancient type of water well unique to the Musashino region of Japan. These water wells are so named because they were dug down in spiral shape. Similar structures were found in the Izu Islands.[1]
History
"Maimaizu-ido" means "snail well" in the Tama dialect of Japanese. This type of well dug in a spiral shape looks like a snail shell from above. Water wells were dug in spiral form, as drilling vertical wells in the loam soil of Musashino Plateau caused the risk of landslides. The soil is too fragile to dig down while the veins of groundwater were particularly deep in the area. Maimaizu wells were one of the main sources of drinking water for Tokyo and the surrounding areas during the Middle Ages.[2]
To build a maimaizu-ido, one has to dig a spiral pit first and create a path leading down, bypassing the layers of soft loam, before finally digging vertically at the bottom to strike water. Because of the difficulty of the process, the phrase "well of difficult digging" (ほりかねの井, horikane-no-i) was a poetic epithet associated with the Musashino region in the early Middle Ages.[3]
Wells
Ome-Shinmachi maimaizu-ido
It is located in the Shinmachi area of Ome and is a large maimaizu-ido. It is believed to have been built 400–500 years ago by travelers on the Ome-Chichibu road. The well is 33 meters wide and 7 meters deep. The well site was discovered in 1987 and restored in Oido Park that year due to its historical significance.[2]
Gonokami maimaizu-ido
It is located in Gonokami Shrine, Hamura. Although it is believed to have been built in the XIII-XIV centuries, according to local legend, it was built in circa 806–810. The well, which provided the drinking water for the nearby village, was restored in 1741 and continuously used until 1960. Designated by the prefecture as a historic site, the well is 16 meters wide and 4.3 meters deep.[3]
