Kirishima Tenbou Kouen

Kirosan Observatory Park is a spectacular viewpoint located at the southern tip of Oshima in Imabari, Ehime Prefecture. Known as one of the signature viewpoints along the Shimanami Kaido, it lies within Setonaikai National Park. From the observatory park near the summit of Mount Kirosan, at an elevation of 307.8 meters, visitors can enjoy panoramic views of the Kurushima Kaikyo Bridge, the islands of the Seto Inland Sea, and the currents of the Kurushima Strait, one of Japan’s three major tidal straits.

The view is often described as the finest along the Shimanami Kaido, and on clear days, Mount Ishizuchi, the highest peak in western Japan, can be seen in the distance. The park is also renowned for its beautiful sunsets and night views. On days when the Kurushima Kaikyo Bridge is illuminated, visitors can enjoy its magical nighttime scenery.

## Overview of Kirosan Observatory Park

Mount Kirosan is located at the southern tip of Oshima and offers an ideal location overlooking the Seto Inland Sea.

From Kirosan Observatory Park, developed near the summit, a vast panorama of the islands of the Seto Inland Sea unfolds before visitors, allowing them to fully appreciate the region’s celebrated beauty of countless islands. The scenery viewed from the observatory takes on different expressions depending on the season and time of day, attracting many tourists and photography enthusiasts.

In 2017, “The Kurushima Strait Viewed from the Summit of Mount Kirosan” was selected as one of the 88 Scenic Views of Shikoku in recognition of its outstanding beauty.

Also in 2017, the park was ranked second in TripAdvisor’s “Japan’s Best Viewpoints Chosen by Travel Lovers” ranking.

## The Observatory Designed by Kengo Kuma

Another major attraction of Kirosan Observatory Park is its observatory, designed by the world-renowned architect Kengo Kuma.

Completed in 1994, the observatory was designed based on the concept of “erasing architecture.”

Rather than making the building itself stand out like a conventional observation deck, the structure was incorporated into the ground so that it blends seamlessly with the surrounding natural landscape. From outside, the building is barely visible, creating a unique design in which only the observation deck appears to emerge from and merge with the terrain.

The observatory is highly regarded as a work that embodies Kengo Kuma’s design philosophy of “erasing architecture.” The curved design of the passageways and walls leading to the observation deck is also worth seeing. The opportunity to appreciate not only the scenery but also the architecture itself is one of the park’s distinctive attractions.

## Spectacular Views of the Kurushima Kaikyo Bridge

The main highlight of the observatory is the Kurushima Kaikyo Bridge stretching out directly before it.

With a total length of approximately 4.1 kilometers, the Kurushima Kaikyo Bridge is the world’s first three-span suspension bridge and a landmark of the Shimanami Kaido.

From the observatory, visitors can see the entire bridge and enjoy a magnificent landscape created by the massive structure and the blue waters of the Seto Inland Sea.

Large vessels and ferries can also be seen passing beneath the bridge, offering a glimpse of the scenery unique to the Kurushima Strait, a major maritime transportation route.

## The Kurushima Strait: One of Japan’s Three Major Tidal Straits

The Kurushima Strait is one of Japan’s three major tidal straits, along with the Naruto Strait and the Kanmon Straits.

The currents can reach speeds of up to approximately 10 knots, or about 18 kilometers per hour, and complex tidal boundaries and whirlpools may sometimes be observed.

From the observatory, visitors can watch the streaks and whirlpools formed by the currents on the surface of the sea, providing a vivid sense of the dynamic natural forces of the Seto Inland Sea.

Because the currents change depending on the time of day, another attraction is the opportunity to enjoy different scenery each time you visit.

## Panoramic Views of Mount Ishizuchi

On days with favorable weather, visitors can see Mount Ishizuchi, the highest peak in western Japan.

A celebrated mountain representing the Shikoku Mountain Range, Mount Ishizuchi creates a breathtaking landscape together with the distant mountain ranges and the islands of the Seto Inland Sea.

From the observatory, visitors can also see islands along the Shimanami Kaido, including Omishima and Hakatajima, and enjoy the characteristic beauty of the Seto Inland Sea’s many islands.

## A Notable Sunset Viewpoint

Kirosan Observatory Park is also famous as a prime location for viewing sunsets.

In the evening, the setting sun turns the surface of the Seto Inland Sea golden, while the silhouettes of the Kurushima Kaikyo Bridge and the surrounding islands emerge beautifully against the sky.

The position of the setting sun changes with the seasons, allowing visitors to enjoy a different landscape in spring, summer, autumn, and winter.

The magic hour, when the sky and sea are dyed red, is especially popular with photographers and attracts many camera enthusiasts.

## Night Views and Bridge Illumination

After dark, Kirosan Observatory Park becomes one of the premier night-view locations along the Shimanami Kaido.

The lights of Imabari spread out below, and on days when the bridge is illuminated, visitors can enjoy the Kurushima Kaikyo Bridge in its fantastical nighttime form.

The bridge may be illuminated on special occasions and during events, creating a spectacular view resembling a gigantic band of light floating on the sea.

The lights of fishing boats and cargo ships are also scattered across the water, creating a romantic atmosphere that is entirely different from the daytime scenery.

## A Popular Destination for Cyclists

The Shimanami Kaido is known worldwide as a cycling route, and Kirosan Observatory Park is a coveted destination for cyclists.

However, the road to the summit is quite steep.

From the Blue Line junction on Oshima to the observatory, cyclists must climb a section approximately 3.6 kilometers long. The average gradient is around 8%, with some sections exceeding 10%.

It is by no means an easy climb, but the sense of accomplishment upon reaching the summit, along with the spectacular views, makes the effort worthwhile, and many cyclists take on the challenge. Those visiting by bicycle should pay close attention to their physical condition, the weather, and traffic conditions.

## The Natural Environment of Setonaikai National Park

The area around Kirosan Observatory Park is designated as part of Setonaikai National Park, preserving a rich natural environment.

Walking paths and viewing areas have been developed around the summit, allowing visitors to stroll while enjoying seasonal flowers and the natural beauty of the Seto Inland Sea.

The fresh greenery from spring through early summer is particularly beautiful, while autumn is an ideal season for enjoying the clear air and far-reaching views.

## Summary

Located near the summit of 307.8-meter-high Mount Kirosan at the southern tip of Oshima, Kirosan Observatory Park is one of the most spectacular viewpoints along the Shimanami Kaido. From the observatory, visitors can see the Kurushima Kaikyo Bridge—the world’s first three-span suspension bridge—the Kurushima Strait, one of Japan’s three major tidal straits, the islands of the Seto Inland Sea, and, on clear days, Mount Ishizuchi, the highest peak in western Japan.

The observatory, designed by world-renowned architect Kengo Kuma to harmonize with the natural surroundings, is another major attraction, allowing visitors to appreciate both the scenery and the architecture. The park also reveals a variety of beautiful faces throughout the day, from sunsets and night views to the Kurushima Kaikyo Bridge illuminated at night.

“The Kurushima Strait Viewed from the Summit of Mount Kirosan” has been selected as one of the 88 Scenic Views of Shikoku, making Kirosan Observatory Park one of the must-visit scenic destinations when exploring the Shimanami Kaido.