Onshi Hakone Koen Park

The Imperial Summer Retreat

The shores of Lake Ashi in Hakone have been a popular spot for people to enjoy the beautiful views, surrounding nature, and cool summers. The appeal of this wonderful natural setting has drawn and mesmerized people for centuries. In the heart of the lake is the former summer villa for the Japanese Imperial family.

The former grounds of the summer villa are now known as Onshi Hakone Koen Park with beautifully manicured Japanese gardens, some of Hakone’s best views, and the reconstructed main building of the complex that once served emperors and foreign dignitaries. The park’s appeal is in the serenity of the wonderful surroundings and a sense of the history that this small area once had. Visitors can imagine foreign dignitaries learning about Japan during the interesting and complex geopolitical atmosphere of the late 1800’s.


The park is easily accessed from one of the two ports for the sightseeing ships servicing Lake Ashi. Walking the spacious grounds gives you a chance to find a quiet place away from the many popular sights in Hakone and gives you an interesting introspective into the life of the Japanese Imperial family. Onshi Park is one of Hakone’s hidden treasures because of the lack of promotion, which is great for those fortunate enough to discover this hidden gem of a spot.

Designs for the villa started in 1884, and was meant to be a secluded and private place for the Emperor’s family and social elite to spend their summers away from the sweltering heat of Tokyo. A German physician, Dr. Erwin Balz, is credited with the initial development plans for the palace. Dr. Balz became enamored with the potential healing benefits of the Japanese hot spring, the Onsen. He chose a small peninsula jutting out into Lake Ashi for it’s geographic characteristics and views of Mt. Fuji.

The palace was completed in 1886, designed in a Western architectural style with large dining halls, balconies, chandeliers, and large mirrors. The Imperial Summer Palace was meant to be a statement of Japanese ascension to the level of the “Western” powers and culture of the late 19th century. Many foreign dignitaries were hosted and stayed on the grounds and buildings. In 1922 Prince Edward of England stayed and spoke highly of his experience here in Hakone.

Unfortunately the majesty of the Imperial Villa in its original state was short lived. Significant damage in the Great Kanto Earthquake of 1923 and the North Izu Earthquake of 1930 left the grounds unusable. Subsequent constraints of the budget left the area in disrepair for a number of decades, but the gardens kept their beauty.

In 1945 the ground were given to the Kanagawa Prefectural Government and soon opened to the public. The main hall of the Imperial complex was rebuilt and now gives visitors a chance to see the grandeur of it’s glorious past. Inside the remade structure is an informative museum and cafe where you can sit, relax, and take in the views.

Onshi Park is easily accessed from the ports of Moto-Hakone and Hakone that service the sightseeing boats traversing Lake Ashi. The park is conveniently located next to the historic towering cedars of the Old Tokaido Road and Sekisho Barrier Gate. It is easy to over look the park and miss the entrance, but this is what makes it so appealing and a wonderful experience for those who do find it.

Join us on a guided tour of one of Hakone’s most loved hidden treasures. Walk the grounds, enjoy the views, and discover for yourself why this was a place designated for royalty and you.