The museum sits exactly on the 135-degree East longitude line, the reference point for Japan Standard Time (JST).
The planetarium houses a Zeiss Model IV projector that has been in continuous use since the facility opened in 1960.
The building's iconic 50-meter-high tower functions as both a scientific observatory and a landmark for time-zone awareness.
It contains a collection of 'Wadokei,' traditional Japanese clocks that used a variable-hour system based on the sunrise and sunset.
The facility is registered as a Tangible Cultural Property of Japan due to its architectural and scientific history.
The Akashi Municipal Planetarium, also known as the Akashi City Astronomical Science Museum, is distinguished by its location directly on the 135th meridian east, which defines Japan Standard Time. The facility features a historic Zeiss planetarium projector, one of the oldest operational units in the world. Visitors can explore permanent exhibits detailing the history of timekeeping, the development of Japanese clocks, and space exploration technology. The building is topped with an observation deck that provides a panoramic view of the Akashi Kaikyo Bridge and the Seto Inland Sea. It serves as a regional center for astronomical education and holds official status as a site of historical significance for Japan's time measurement.
The observation deck overlooking the Akashi Kaikyo Bridge against the backdrop of the Seto Inland Sea.
Visit the observation deck on the top floor first to orient yourself with the surrounding Akashi coastline.
Check the planetarium show schedule upon arrival, as live commentary sessions vary by theme and audience age.
The museum gift shop carries unique JST-themed merchandise not found elsewhere in Japan.
Do not mistake the planetarium's main tower for a standard lighthouse; while it serves as a beacon, it is a scientific facility.
Closed on Mondays and during occasional facility maintenance periods.
