When it was built in 1999, Japan's Subaru Telescope was the most expensive observatory constructed, until ground was broken on the nearby Thirty Meter Telescope. The 22-ton mirror, reaching 27ft in diameter, is one of the largest optical mirrors in existence. Observatory tours, which don't include looking through the telescope, are given in Japanese or English but not both, so sign up early for your preferred language. Reserve tours online at least one week in advance.
Children under 16 years old are not allowed on tours and there are no public restrooms. Incidentally, Subaru is the Japanese word for the Pleiades constellation.
