太閤下水

When Toyotomi Hideyoshi built Osaka Castle the streets were laid out on a grid, and drains were dug along the line where the backs of the buildings met. The blocks of forty ken square between those drains became the basic unit of the town plan. The drains are called sewari-gesui, or Taiko-gesui. The city designated them a cultural property in December of Heisei 17 (2005).

Translated from the Osaka Prefecture and Osaka City tourist listings (観光施設一覧, CC BY 4.0).