If you’re in Tokyo this summer, or you will be soon, you know it’s pretty sweltering out there. The best way to keep cool? Chill out (literally) in the water! Read on for the best spots to do that in Tokyo, and the surrounding regions.

① Yomiuriland’s Pool Wai

Our first choice for summer fun is the water park inside Yomiuriland, Tokyo's largest amusement park. It's been around for almost 60 years! These days, summer means the opening of Pool Wai, a water park quite popular among local Tokyoites.

The wave pool slopes down gently, but goes to a depth of 1.4 meters (4'7"), with waves cresting at about 60 cm (2'). Between July and September or so, daily performances are held on a stage in the middle of the beach-like wave pool. The "Catch the Wave" show starts at 16:00!

We rather like the park's lazy river, though, where you can rent floaties made for two people to sit together.

Plus, don't miss the diving pool. There are diving platforms at three heights: .5 m, 1 m, or 2 m (1' 8", 3' 3", or 6' 7").

Perhaps best of all, and extremely popular among the young adults of Japan, is Pool Wai's "night pool." This isn't a separate pool; Yomiuriland stays open late into the evening, turns on flashy night-time lighting, and creates a space aimed towards a slightly older demographic than usual. With cool music and special events, you'll see a lot of people in their teens and twenties at night.

▶ More on Yomiuriland's Pool Wai.

② Toshimaen’s Water Park & Niwa no Yu (庭の湯)

Toshimaen (豊島園) has its own lengthy history in Tokyo, and has the cool retro look to prove it. The water park portion of Toshimaen opens every summer, and it's a straight shot, in just about 30 minutes, from Ikebukuro Station (池袋駅).

Image Source: Official Website

Like any good water park, Toshimaen is home to plenty of pools, lazy rivers, slides, and fun rides that will get you good and soaked. They even have do a night pool, like Yomiuriland. For more details on the water park, check out the official website (jp).

▶ More on Toshimaen year-round.

You can also take a little three-minute walk over to enjoy the water at Niwa no Yu, Toshimaen's own hot spring bath. If you're thinking "oh no, I don't do naked public baths," then don't worry – you can take a dip in your bathing suit, too.

If the water park seems a little loud and rambunctious for you, spend a relaxing afternoon at Niwa no Yu. There might not be any slides or rides here, but the pools are filled with all-natural hot spring water!

▶ More on Toshimaen's Niwa no Yu.

③ Tokyo Summerland

Image Source: Official Website

Between Yomiuriland, Toshimaen, and Tokyo Summerland, you've got Tokyo's three biggest pools!

One of the features that makes the place especially popular is a separate doggy area! Bring your dog, and you can all spend some time cooling off in the water. Or, if you're just passing through Tokyo sans-dog, go to the dog area to say hello to some local pooches.

Image Source: Official Website

With pools outdoors and indoors, and a number of different attractions, the park draws crowds of all ages. I mean, wouldn't you want to go down a watermelon slide?

Image Source: Official Website

Tokyo Summerland's Snake Slide is both the park's oldest, and its most popular slide. Slide down and you'll slip along serpentine curves, swinging this way and that!

▶ More on Tokyo Summerland.

④ Hakone Kowakien Yunessun (箱根小涌園ユネッサン)

Located in Hakone, a quick trip from Tokyo, Yunessun is a hot spring water park. At a glance parts of it might look like your standard water park, and guests do wear swimsuits, but all the water really is from a natural hot spring! You've probably seen pictures of Yunessun before, since their novelty baths filled with things like green tea and wine are always a hit around the internet, but the park has a huge variety of facilities.

Water park-style attractions, novelty baths, plus indoor and outdoor pools filled with hot spring water.

The best part of the simpler baths and pools? The amazing views of Hakone! You can look out onto the lush natural greenery while enjoying the natural spring water. In Japan people tend to only visit hot springs in the winter, but Yunessun is really working to break that habit, offering a variety of summer fun.

▶ More on Hakone Kowakien Yunessun.
 

⑤ Sunvalley Nasu Resort

A little north of Tokyo, in Tochigi Prefecture, you'll find the resort hotel Sunvalley Nasu. The hotel, surrounded by natural forests offers nine different kinds of lodgings, but more importantly there are a variety of open-air hot spring baths and pools!

Literally steps away from the surrounding rooms, the main pool is heated, and open most of the year (except during winter months, when it just gets a bit too cold!)

Get into the resort atmosphere and sip a colorful cocktail as you lounge by the pool. (About 800 yen each.) It's a little like a tropical beach resort, except you're surrounded by fewer palm trees and more evergreens!

▶ More on Sunvalley Nasu.