The Odoi (御土居) was an earthen berm, erected at the very beginning of 1591 by Toyotomi Hideyoshi (豊臣秀吉).
Standing just short of 5m tall, the 22.5km embankment encircled the city with an outer moat (where there weren't rivers) and numerous 'gates'.
Straddling the Tenjin-gawa (used in place of a moat along this stretch of the Odoi), Uguisu-bashi (鶯橋) is so-named because bush warblers were once common here.
Although the city limits had moved beyond the berm by 1630, the Odoi existed remarkably intact until the late 19thC.