The name 'Kujūku-shima' translates to '99 islands', though the archipelago actually consists of over 200 distinct islands and islets.
The observatory was selected as one of the 'Top 100 Sunset Spots in Japan'.
The flower garden at the base is maintained through community efforts and spans approximately 4,300 square meters.
The site sits at an elevation that allows for clear visibility of both the Sasebo Bay entrance and the open waters of the East China Sea.
Tenkaiho Observatory provides an elevated vantage point overlooking the Kujūku Islands within Saikai National Park. The facility features a multi-tiered concrete observation deck offering a 360-degree panorama of the complex island chain. It is located on the western tip of the Funakoshi Peninsula in Sasebo, Nagasaki. The site is widely recognized as one of the best locations to view the sunset over the islands. Below the observation area, a large flower garden is cultivated, featuring rapeseed blossoms in the spring and cosmos flowers in the autumn. The site is maintained as a public space and serves as a major trailhead for local hiking trails connecting to the surrounding coastal cliffs. The observation deck is accessible via a short walking path from the adjacent parking lot.
The highest point of the wooden deck provides the clearest, unobstructed wide-angle view of the island clusters.
Bring a polarizing filter for your camera to reduce glare from the water during bright daylight hours.
Visit during the peak flowering weeks in spring or autumn to photograph the islands framed by seasonal blooms.
Dress in layers, as the elevated, exposed position of the deck makes it significantly windier than at sea level.
Do not rely on walking or cycling from Sasebo city center, as the terrain is steep and the distance is significant.
