Sumida River
Tsukiji is built on reclaimed land out of what were once lowland marshes along the Sumida River delta. Throughout the Tokugawa period, earth from the shogunate's extensive moat and canal excavations was systematically used to fill in the marshes along the river, creating new commercial districts and waterfront housing. The land was then named Tsukiji (築地), meaning "constructed land" or "reclaimed land".