2026 Toyama Park Splash Pond Full-Day Course

Toyama Park in Shinjuku City has a free water-play area open only in summer, the Toyama Park Splash Pond (Hakoneyama Area). The 2026 season runs from Wednesday 1 July to Wednesday 30 September, 10:30-15:30. It closes for cleaning and inspection on Wednesday 5 August and Thursday 3 September, and other days may also be suspended depending on weather and temperature. The venue is Toyama Park (Hakoneyama Area) in Shinjuku City, a park created on the site of the former Owari Tokugawa family villa; within it stands Mt. Hakoneyama, the highest point inside the Yamanote Line loop. The splash pond is a shallow pond fitted with a slide, admission is free, and there are toilets in the park. Tents may not be pitched, so use tree shade and a picnic sheet for sun protection. In the morning, visit Natsume Soseki's study at the Soseki Museum and pay your respects at Ana Hachimangu Shrine. At lunchtime, open your bento on the park lawn, then climb Mt. Hakoneyama before heading into the water. It is a day around the Waseda area, walking through greenery and slopes you would never expect in the city centre.