Takashima Castle is a Japanese castle located in Suwa, central Nagano Prefecture, Japan. At the end of the Edo period, Takashima Castle was home to the Suwa clan, daimyō of Takashima Domain. The castle is also known as ’The Floating Castle of Suwa’’’ or Shimazaki Castle

Suwa is a city located in Nagano Prefecture, Japan. As of 1 March 2019, the city had an estimated population of 48,972 in 20698 households, and a population density of 452 persons per km². The total area of the city is 109.17 square kilometres (42.15 sq mi).