Iiyama is a city located in Nagano Prefecture, Japan. As of 1 February 2019, the city had an estimated population of 20,118 in 7372 househ…Iiyama is a city located in Nagano Prefecture, Japan. As of 1 February 2019, the city had an estimated population of 20,118 in 7372 households, and a population density of 99 persons per km². The total area of the city is 202.43 square kilometres. It markets itself as "Japan's Hometown" and is known as the "Little Kyoto of Snow Country".