Mizusawa Onsen

Mizusawa Onsen is found in Oshu, a city in southern Iwate Prefecture that incorporates the historic town of Mizusawa, home to one of Japan's most significant observatories — the Mizusawa VLBI Observatory, originally established in 1899 as the International Latitude Observatory and one of only six stations worldwide that contributed to the original measurement of the Earth's wobble on its axis, making this modest Tohoku observatory a landmark of international geodetic science. Mizusawa was also a prosperous castle town on the Oshu Kaido, the great northern highway that connected Edo with the Tohoku domain capitals, and its well-preserved traditional townscape retains echoes of this post town heritage. The onsen here draw on silica-rich geothermal resources from the Kitakami Highlands, providing mineral bathing in a city whose combination of scientific heritage, historical highway culture, and access to the southern Iwate countryside makes it a rewarding stop on any thorough exploration of Tohoku's heritage.