Tsukuba is a city located in Ibaraki Prefecture, Japan. As of January 1, 2024, the city had an estimated population of 256,526 in 121,001 households and a population density of 900 persons per km2. The percentage of the population aged over 65 was 20.3%. The total area of the city is 283.72 square kilometres (109.54 sq mi). It is known as the location of the Tsukuba Science City , a planned science park developed in the 1960s.

Ibaraki Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Ibaraki Prefecture has a population of 2,828,086 and has a geographic area of 6,097.19 square kilometres. Ibaraki Prefecture borders Fukushima Prefecture to the north, Tochigi Prefecture to the northwest, Saitama Prefecture to the southwest, Chiba Prefecture to the south, and the Pacific Ocean to the east.