Nagashima Water Park With Kids: Our Experience at Nagashima Jumbo Seawater Pool
Last Updated on April 16, 2026 by Kay
This post may contain affiliate links, meaning I may earn a small commission on any purchases through those links at zero additional cost to you. Whatever I make goes to keeping this website running and I am forever grateful for the support. See my Privacy Policy for more information.
Nagashima Jumbo Seawater Pool is the biggest waterpark in Japan, and (perhaps unsurprisingly), I found that it is amazing for kids of all ages.
So if you’re wondering whether going to Nagashima Water Park with kids is a good idea, it absolutely is, even for toddlers and babies. After visiting Nagashima Jumbo Seawater Pool with my daughter, I feel like this is one of the better family-friendly water parks in Japan if you know where to focus your time.
What surprised me most was how much there was for younger kids beyond the big headline slides. There were shallow splash zones, an indoor kids’ area as well as a spacious outdoor children’s area, and enough open space for little kids to move around without everything feeling too intense.
And if you have older kids, don’t worry, there are also lots of thrilling slides and pools for adults and older kids to enjoy.
That said, it is not perfect. The water felt colder than I expected, some of the larger rides are definitely not for little kids, and the waterslides closed earlier than I would have liked. But overall, I do think Nagashima Water Park is worth visiting with kids.
In this article, I’ll share my experience visiting Nagashima Water Park (Jumbo Seawater Pool) with my family so that you know what to expect if you decide to visit. As my daughter was six years old at the time and too short for many of the water slides outside of the kids’ area, I’ll just be covering what’s available for kiddos under 120 cm tall.
If you have older children, notably those taller than 120 cm (about 4 feet), who like thrilling water slides, I recommend reading my general article on Nagashima Water Park.
Table of Contents
Is Nagashima Water Park Good for Kids?
Located in Nagashima Spa Land, Nagashima Water Park is great for kids, particularly if your child enjoys splash pads, shallow pools, small slides, and interactive play structures.
From my visit, this did not feel like a water park that only caters to thrill seekers. The family areas were not just an afterthought. There were multiple zones where younger children could actually play, explore, and repeat the same activities without getting bored after ten minutes.
The biggest strength for families is the variety. You have outdoor shallow play areas, colorful mini slides, water-play structures with spraying features, an indoor kids’ area that is perfect for babies and toddlers, a baby-friendly warm pool, and a lazy river and wave-style pool.
All of that makes it super easy to spend several hours here with children of different ages.
Best Areas at Nagashima Water Park for Babies, Toddlers, and Younger Kids
There are two main kid-oriented areas at Nagashima Jumbo Seawater Pool: an indoor area called Super Kids and an outdoor area called JAPAAAAN!
Personally, I think the indoor area (Spa Kids) is best for babies and toddlers, while the outdoor area (JAPAAAAN) is better for preschools and lower elementary-aged children. Here’s what you’ll find in each area and what my daughter thought about it (age six when we visited).
Spa Kids (スパキッズ)
You’ll see this indoor play area to your left, right after you enter the waterpark. It’s a great place to escape the sun and has lots for little ones to do. Also, if the water in the outdoor area feels a little cold (as it did to me), you’ll be pleased to know that the water here is warmer.
Note that you cannot bring swim rings inside. As you’ll see in the photo below, people leave their swim rings outside. (Make sure to write your name on your swim ring beforehand if you’re worried about theft.)
Inside Spa Kids (written as スパキッズ in Japanese), there are small slides, splash pads, interactive water features, and a lukewarm, baby-friendly hot spring pool in the indoor kids’ area on the second floor.
The water in this area is shallow, about 10 cm to 30 cm, and clearly marked, which makes it much better for toddlers and babies than the main pools. And don’t worry, just like the rest of the park, there are lifeguards here as well.
The Aqua Deck, pictured below, has a 20 cm pool and 5 water slides for kiddos.
The Omocha (Toy) Pool, pictured below, has lots of water sprays. My daughter loved this spray area; she said she felt like she was in the ocean.
How cute are these little swings for babies and toddlers in the following picture? My six-year-old was too big for these, so I wish I had a baby to try these out with!
This is the Picha Picha (Splash Splash) Pool. With water only 10 cm deep, it’s especially perfect for one-year-olds.
There is also a very gentle wave pool for little ones where they can sit on their parent’s lap and enjoy the water swaying back and forth.
Notably, the regular onsen pools outside were very hot, but the indoor kids’ versions were much more manageable for little ones. My daughter absolutely loved it and didn’t want to leave!
Also, if you’re wondering if this area is only for babies and toddlers, it’s thankfully not. My daughter (age six) had a great time here.
In particular, we loved the little pink slide where we could ride down on a double inner tube. I think we did that more times than I can count because there was hardly any line!
As you can see in the photo above, there are plenty of colorful, smaller slides as well that are perfect for toddlers (or babies if you hold them while going down).
My daughter also loved these water guns on the second floor (don’t worry, it doesn’t spray anyone below). The red sign in the photo below (between the two guns) reads, “Make sure to take turns!”
Overall, my daughter said the indoor splash pad was fun (“tanoshikatta”).
JAPAAAAN
This is located towards the back of the park, right by the wave pool (Surfin’ Pool).
This zone has the kind of features that work well for preschoolers and younger elementary-aged kids: a massive sprayground with slides and low climbing structures that are interactive, water sprays, tipping buckets, and shallow water.
My daughter was obsessed with this area, and she spent the day happily running up, sliding down, running through the water, trying out all sorts of levers and dials, and then doing it all over again. As you can see in the photo below, she had to figure out how to get the water to stream from the top spout to the bottom, which I thought was great for her curious little mind.
Parents can join in on the fun too, which is what my husband and I did, and it was really, really enjoyable. There was so much to do that we don’t blame her for having to be forced to take breaks!
Apart from the tube slides located throughout the splash pad, there are two sets of kid-friendly waterslides in this area. One is only for children who are elementary-school age and younger. Guests over the age of 12 cannot use these slides.
The other slides, pictured below, can be used by children and parents, so my husband and I took turns going down and “racing” with our daughter. (She always won!)
(If your kiddo is under 120 cm and you want to go on the more intense waterslides, take turns like my husband and I did! One of us watched the kiddo while the other enjoyed some slides. Sure, you’ll have to ride with some strangers for some of the thrilling waterslides, but it was totally fine when I went.)
I also liked that this kids area looked visually bright and playful rather than intimidating. The colorful structures, small slides, and shallow water made it feel much more fun and engaging for our daughter, and for other young children as well! Everything seemed new and well-maintained as well.
My daughter said the outdoor sprayground was really fun, especially when she saw her dad get soaked by a massive bucket of water.
There is also this fun area behind the huge splashpad or sprayground where kids can run around (the slides for elementary school kids and under are in the picture below as well).
Other Family-Friendly Pools
There are seven pools at Nagashima Water Park. I already covered one above, which is JAPAAAAN, and I think four others are very kid-friendly, so allow me to explain.
Surfing Pool
Across from JAPAAAAN you’ll see Nagashima Water Park’s famous Surfing Pool. This pool has no minimum height requirement. However, it does turn into a wave pool about twice an hour with J-pop music playing in the background and water spraying about.
As you can see in the picture above, my daughter was in an inner ring when we were in this pool, as it goes a little deep (from 0 cm all the way to 160 cm), and she doesn’t know how to swim. (I know, I know, we’re trying to put her into swimming lessons, but she keeps refusing because she’s apparently a cat and cannot get wet. And yet she likes waterparks. Make it make sense.)
The light blue area is quite shallow, though, so lots of babies and toddlers were splish-splashing there.
My daughter said this pool was fun because the water was deep, but she was able to go because she had her swim ring, and she liked the music.
Pyon Pyon Dobon
Make sure to also try out the ぴょん・ぴょん・ドボン！Pyon Pyon Dobon (which is the sound of hopping and then splashing down). This pool is like a little athletics course. Parents can walk with their kids or try the course themselves.
My daughter said she almost cried when she fell but she enjoyed it overall because she liked watching her dad fall and she was able to complete the course.
This pool allows guests who weigh under 65 kg and are between the ages of 5 and 35 (my husband is over 35, but the staff didn’t ask his age, so he tried it. Also, what’s up with that cutoff anyway? It’s not like people over age 35 would be at risk of seriously injuring themselves on a course like this…. I know Japanese companies don’t like to hire people over 35 for entry-level positions, but pools having that kind of age restriction are bonkers! Okay, rant over).
Family Pool
Right next to the Pyon Pyon pool is a shallow family pool that is perfect for families with babies.
Lazy River
The next kid-friendly pool I recommend is the Lazy River. It’s not a must but if you feel like you want to laze around in an inner tube (which you need to already have with you) and get pulled along the current, then go on this. It can get crowded, though.
Onsen Pools
There are two onsen pools but we found the water was too hot for our daughter, and she refused to go in for very long. And this is a girl who has been going to onsen since she was a toddler, so trust me when I say that it’s hot. (Stick to the indoor onsen pool.)
Lastly, there’s the Extreme Rapids Pool, which has a minimum height requirement of 130 cm. However, children between 120 cm and 130 cm can go to this pool if they wear a lifejacket (which I believe you need to rent for 1000 yen, but you can use it the entire day).
As the name suggests, the Extreme Rapids Pool is not exactly for relaxing. You ride in an inner tube, and you’re pushed along a current that has the occasional strong wave. Since you need to be in an inner tube for this pool (attraction, maybe?), I feel like it would be hard to always stay right next to your child all the time, since they’re in a tube too and being tossed around.
It is fun, though, and there are plenty of lifeguards, so I hope to go with my daughter when she’s taller because I loved the experience.
What Older Kids Might Enjoy More
If you are visiting with older kids, there is a lot more to do beyond the children’s areas. In fact, there are nine other waterslides that they can enjoy, as well as an intense lazy river.
However, as mentioned earlier, many of the waterslides outside the kids area are for riders at least 120 cm tall (some even requiring a minimum height of 130 cm or 140 cm).
Even if your kids meet the height requirement, some of these slides are quite intense and might scare younger children, especially if they’re not used to thrilling rides. For more detailed information on these waterslides, read this article.
Tips for Visiting Nagashima Water Park with Kids
There are a few things I think every parent should know before they go to Nagashima Jumbo Seawater Pool with kids.
Stay at Hotel Nagashima for Early Entry
We stayed at Hotel Nagashima and were able to enter the park 15 minutes earlier than the general public who didn’t stay there. This made a huge difference because although the number of people who had early entry seemed like a lot initially, once we got into the park they dispersed quickly and it felt super manageable to take everything in and plan what to do.
In fact, there was zero wait time for waterslides and my daughter practically had the children’s areas to herself for around thirty minutes!
Some inner tubes are heavy to carry
Some rides use one- or two-person inner tubes or rafts, and from personal experience, carrying them up a lot of stairs can be exhausting. I struggled with a one-person inner tube, and I can’t imagine having to carry a two-person one when my daughter is tall enough to go on those slides (because let’s face it, she won’t be able to help much).
Note that the slides close early
All of the waterslides closed by 3:55 PM on my visit, which is why I was especially glad that I got early entry on that day and went on the waterslides while my husband watched our daughter (and then we switched).
The park works best with a loose plan
For families, I think the best approach is the following (what my family did).
Start with the bigger (thrilling) slides if your kids meet the height requirements (the slides are listed in this article but are a minimum of 120 cm or 130 cm for most).
If your kids don’t meet the height requirement or are too scared, have one parent go on the bigger slides while the other plays with the little one(s) in the kids’ splash areas. Some of the slides are close together, so just go down them all one after another because walking to and from the kids’ areas, switching, and then going back to the slides is a waste of time. Not to mention finding the parent while they’re running around with the kid(s) is also a time suck. (And they likely won’t notice their phone buzzing, from my experience.)
If your kids are outside all the time, try to take them into the indoor area for a reset, or have them enjoy something to eat or drink. And thankfully, there are restaurants here.
Make sure to refuel
There are several areas where you can eat. We enjoyed the restaurant near the entrance, where my daughter could sit down and have some shaved ice (kakigori).
Know Where to Keep Your Things
There is also a building right next to this restaurant where people keep their things on the second floor, which is what we did.
But of course, for the most security, use the coin lockers next to the entrance. At 500 yen, these lockers are pricey, so make sure you have several 100 yen coins with you if you want to use them.
The showers are located at the back and are free.
Absolutely Consider Visiting the Amusement Park
As mentioned earlier, Nagashima Jumbo Seawater Pool (the water park) is located within Nagashima Spa Land, an amusement park. This amusement park is fantastic for families with children of all ages.
To know more, make sure to read my article about Nagashima Spa Land’s amusement park.
I recommend visiting the amusement park on a separate day, either the day before or after the water park, if you want to experience it fully without feeling rushed.
Final Verdict: Is Nagashima Water Park Worth It with Kids?
Visiting Nagashima Water Park with kids is so worth it.
What makes it work is not just the thrilling slides. It is the combination of family-friendly features: the outdoor splash structure, the smaller slides, the indoor kids’ area, the warm baby-friendly pool, the lazy river, and the open pool space.
The main downsides are the colder water, the early slide closures, and the fact that some attractions are clearly better for bigger kids than for younger ones. But if you go in expecting to focus on the family areas rather than treating the whole park like a thrill-slide destination, it can be a really good day out.
For my family, this water park was a place where my daughter had loads of fun, and although she was exhausted, she didn’t want to leave when it closed.
According to my daughter: “It’s GOOD!” (And yes, she yelled the last part, so you know she means it!)