Toyama Park Splash Pond (Hakoneyama Area)
About this spot
The Toyama Park Splash Pond (Hakoneyama Area) is a free water-play area in Toyama Park, Shinjuku City. The 2026 season runs from Wednesday 1 July to Wednesday 30 September, 10:30-15:30. Because it is a shallow pond fitted with a slide, children can not only get into the water but also slide down, which is a big draw for them. It sits at the foot of Mt. Hakoneyama and is surrounded by trees, so shade is easy to find, which is a real help. Admission is free and there are toilets in the park. Tents may not be pitched, so use a picnic sheet and tree shade for sun protection.
Season & hours
Name: 戸山公園 じゃぶじゃぶ池（箱根山地区）
Date & time: 7/1 (Wed)–9/30 (Wed) 10:30–15:30 ※清掃点検休止8/5 (Wed)・9/3 (Thu)、天候や気温により他の日も休止あり
Venue: 新宿区・戸山公園（箱根山地区）
Tips
Cleaning and inspection closures fall on Wednesday 5 August and Thursday 3 September. Other days may also be suspended depending on weather and temperature, so check the opening status before you set out. Tents may not be pitched. Agreeing in advance to take turns on the slide is reassuring. There is no changing room, so wear swimwear underneath or bring a towel poncho.
Best time to visit
Arriving at 13:30 lets you play properly in the calmer light until it closes at 15:30
How was this spot?
Access & map
新宿区・戸山公園（箱根山地区）
Model course featuring this spot
2026 Toyama Park Splash Pond Full-Day Course
Tokyo
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