Nichihara Astronomical Observatory is a public observatory located in the former Nichihara area of Tsuwano Town, Shimane Prefecture. It stands on the summit of Mount Makuraseyama at an elevation of 255 meters, overlooking the area where the Tsuwano River and Takatsu River meet.
Since opening in 1985 as Japan’s first public observatory designed for general visitors, Nichihara Astronomical Observatory has been cherished as a symbol of the region known as the “Hometown of the Stars.”
The observatory is surrounded by dense forest and has very little artificial light nearby. On clear nights, countless stars spread across the sky, and visitors may be able to see the Milky Way and many stars that are difficult to observe from urban areas.
The observatory opened in 1985, the same year that Halley’s Comet made a close approach to Earth and sparked widespread interest in astronomy throughout Japan.
At a time when enthusiasm for space was growing, Nichihara Astronomical Observatory was established so that anyone could enjoy serious astronomical observation. It was an advanced facility for its time and became an important pioneer among Japan’s public observatories.
Dr. Shuzo Isobe of the Tokyo Astronomical Observatory provided extensive technical assistance during its construction, helping incorporate professional astronomical knowledge and technology into the facility.
One of the observatory’s most impressive features is its 75-centimeter reflecting telescope, which is among the largest telescopes in Japan available for public observation.
The telescope uses a prototype mirror developed in connection with the world-famous Subaru Telescope on the summit of Mauna Kea in Hawaii. Its design and operating principles are also based on the same approach used for the Subaru Telescope.
The observatory’s symbolic instrument is its 75-centimeter computer-controlled Nasmyth-type altazimuth telescope. This sophisticated telescope allows visitors to observe celestial objects with remarkable clarity.
The Nasmyth focus system has the advantage of keeping the eyepiece in a relatively fixed position even as the telescope tracks objects moving across the sky. This means visitors do not have to adopt awkward positions while observing, making the telescope comfortable to use even for beginners.
Through the large telescope, visitors can observe details such as the craters of the Moon, the rings of Saturn, and the bands of Jupiter. Under favorable conditions, it may also be possible to observe nebulae, star clusters, and distant galaxies.
Seeing these celestial objects directly through a telescope can provide a very different experience from looking at photographs in books or on screens. The observatory offers children and adults alike an opportunity to deepen their interest in astronomy.
Astronomical observations may also be conducted during the daytime, including observations of the Sun. This makes the facility a place where visitors can explore the universe not only at night but also during the day.
The area surrounding Nichihara Astronomical Observatory is known for its extremely low levels of light pollution. During the 2008 nationwide continuous stargazing survey conducted by the Japan Environmental Association, Nichihara Astronomical Observatory and the Fukui Prefectural Nature Conservation Center were highly rated for having exceptionally dark skies on Honshu, Japan’s main island.
Nichihara was also ranked second nationwide in the survey, behind Hateruma Island in Okinawa Prefecture. These results highlighted the exceptional quality of the night sky in this region.
On a clear night, stars fill the entire sky, creating a scene that truly resembles a “sky filled with falling stars.” The Iwami region also has numerous traditional folk stories associated with stars, reflecting the long-standing connection between the night sky and local culture.
Near the observatory is the Stars and Forest Science Museum, which opened in 1994. The museum introduces not only astronomy and outer space but also forests and the Earth’s environment.
Exhibits explore familiar questions and natural phenomena, such as why sunsets appear red, making the museum accessible and enjoyable for both adults and children.
Videos and three-dimensional displays are used to make scientific subjects easier to understand. The museum also introduces traditional star-related folk stories from the Iwami region, providing a cultural perspective on the night sky.
The neighboring Polan-no-Hiroba Astronomical Materials Museum serves as the reception area for the observatory and also offers free video screenings.
Learning about space and astronomy before an evening observation session can make the experience of looking through the telescope even more enjoyable.
Nichihara Astronomical Observatory also offers a unique experience called “Wishing Star Delivery Service.” Visitors can purchase a special kit, write down a wish, and place it in a dedicated mailbox at the observatory.
The wishes are then taken to nearby Taikodani Inari Shrine, where they are dedicated and ritually burned as part of a traditional religious practice.
The service includes playfully named options such as the “Shooting Star Express Course” and the “Slow Course.” For visitors, writing a wish while surrounded by a beautiful starry sky can become a memorable part of a trip to Tsuwano.
The area around Mount Makuraseyama, where the observatory stands, has been developed as Makuraseyama Forest Park. Covering approximately 13 hectares, the park includes walking trails, gazebos, a waterside recreation area, a suspension bridge, and open forest spaces.
The park provides opportunities to enjoy the natural environment at a leisurely pace throughout the year.
One of the most popular facilities is Makuraseyama Campground. The campground offers views of Mount Aonoyama and the JR Yamaguchi Line, making it a popular location for railway and landscape photography.
Facilities include shower buildings, a management building, and barbecue houses. Visitors can enjoy an outdoor stay during the day and gaze at a sky filled with stars at night.
Because the campground is located next to the astronomical observatory, it is possible to combine camping and stargazing in one trip.
The forest park is also used for school outdoor programs and nature-learning activities, providing an environment where visitors can experience the changing seasons while learning about the natural world.
Weather conditions can change quickly on the summit, so visitors planning to observe the stars should check the weather forecast and the observatory’s observation schedule before traveling.
If stargazing is your main goal, choosing a clear evening will give you the best chance of enjoying the night sky.
Temperatures can drop significantly at night, even during summer, so bringing an extra layer is recommended. The mountain setting is also naturally quiet, making it an ideal place to slow down and spend time looking toward the universe.
From JR Nichihara Station, the observatory is approximately 5 minutes by taxi or about 35 minutes on foot.
By car, it is approximately 45 minutes from the Rokukaichi Interchange on the Chugoku Expressway. From Iwami Airport, the journey takes approximately 25 minutes by taxi.
A trip to Nichihara Astronomical Observatory pairs naturally with sightseeing in historic Tsuwano. During the day, visitors can explore the traditional castle town, historic temples and shrines, and preserved streetscapes. At night, they can leave the town lights behind and look up at the stars from the mountains of Makuraseyama.
The combination of Tsuwano’s history and culture with the region’s exceptionally dark night sky offers a memorable way to experience a different side of Shimane.
Whether you are passionate about astronomy or simply want to experience a beautiful star-filled sky far from the city, Nichihara Astronomical Observatory provides an opportunity to discover the universe in a peaceful natural setting.