Tsukuba

is a city located in Ibaraki Prefecture, Japan. As of July 1, 2020, the city had an estimated population of 244,528 in 108,669 households and a population density of 862 persons per km². The percentage of the population aged over 65 was 20.3%. The total area of the city is . It is known as the location of the , a planned science park developed in the 1960s.