GRAND MONday Resort TOKYO BAY MAIHAMAOUTDOOR POOL Outdoor pool
GRAND MONday Resort TOKYO BAY MAIHAMA
OUTDOOR POOL
Outdoor pool
365 days of pool entertainment
Enjoyable,
Across the seasons
Resort experience
MAIHAMA LAGOON
During the day, enjoy a vibrant resort pool experience with your family or group.
Swim to your heart's content, eat, rest, and relax in the sauna. It's a place where you can spend your time however you like.
From dusk to night, you can relax and enjoy the changing gradations of the sky and the fantastical surface of the water.
In winter, enjoy a warm and cozy hot pool; here you'll find enjoyment that transcends the seasons.
Special memories are created at glamorous events and waterside entertainment.
POOL
Enjoy the sea breeze at our outdoor pool, which includes an adult pool with jets and a children's pool with a depth of 0.4m.
In the summer, it's a resort pool where adults and children can have a blast, and in the winter, it transforms into a relaxing hot pool with heated water, allowing you to enjoy waterside activities 365 days a year.
CABANA[Cabana]
A covered private space called a "cabana" is located poolside. It can be used as a sunshade or a place to relax.
Covered private space located poolside"CABANA" It can be used as a sunshade or resting space.
BARREL SAUNA
[Barrel sauna]
プールサイドには、天然木を使用した本格的なバレルサウナがございます。自然のぬくもりを感じる空間で、心と身体を整える、深いリラクゼーションのひとときをお過ごしください。
※ご宿泊の方のみご利用可能
POOL SIDE BBQ
In the barbecue area, you can enjoy authentic BBQ by the poolside.
During the day, enjoy a lively barbecue with family and friends, and in the evening, transform into a resort-like dinner surrounded by lights and music.
Enjoy a unique dining experience at our hotel, blending the liberating atmosphere of a resort with the joy of food and entertainment, all while gazing at the ocean, the pool, and the endless sky.
- ● Available hours
- 2.5 hours
- ● Business Hours
-
11:30~17:00
(最終入場 14:30 / 16:30 L.O. )
18:00~22:00
(最終入場 19:30 / 21:30 L.O. )
INFORMATION
POOL AREA MAP
- place
- 1st floor outdoor
- Utilization time
-
夏季限定!デイプール営業時間延長(2026年8月31日まで)
デイプールの営業時間を期間限定で19:00まで延長いたします。〈2026年8月31日まで〉
・デイプール 8:00~19:00
・ナイトプール 18:00~22:00
※18:00~19:00は、デイプールとナイトプールを並行して営業いたします。
※ナイトプールは18歳以上の方のみご利用いただけます。
〈2026年9月1日以降〉
・デイプール 8:00~17:00
・ナイトプール (18歳以上) 18:00~22:00【ご宿泊のお客様のご利用時間について】
● チェックイン日
デイプールはチェックイン時間以降よりご利用いただけます。
ナイトプールは18:00~22:00でご利用いただけます。
※チェックイン前はご利用いただけません。
● ご滞在中(ご連泊の場合)
デイプール
8:00~17:00(2026年8月31日まで19:00まで)
ナイトプール
18:00~22:00
● チェックアウト日
デイプールは8:00~12:00までご利用いただけます。
※チェックアウト後はご利用いただけません。
- Pool
-
Pool with jacuzzi, water depth 0.6m
Adult pool, maximum depth 1.2m
Children's pool, water depth 0.4m
- poolside
-
バレルサウナ(定員6名):無料
利用時間 14:00~22:00
※現在、バレルサウナは調整中のため、ご利用いただけません。ご不便をおかけいたしますが、何卒ご理解賜りますようお願い申し上げます。
BBQエリア(6名用・8名用 各2台)
-
利用料金・
ご予約
-
-
Hotel guests
ご利用のお客様はフロントカウンターまでお越しください。事前予約は不要でございます。
● Day pool
*Free for children under 3 years old[Monday to Thursday]
[Monday to Thursday]
Adults: 3,500 yen / Children (elementary school age and younger): 2,500 yen [Friday-Sunday/Holidays]
[Friday to Sunday and public holidays]
Adults: 4,500 yen / Children (elementary school age and younger): 3,000 yen ● ナイトプール
大人 4,000円 ※ナイトプールは18歳以上でご利用いただけます。 -
Day trip customers
混雑状況を顧み、現状日帰り(外来)でのプール利用は受付を停止しております。再開時期につきましては、決まり次第ホームページにてご案内いたします。
● Day pool
*Free for children under 3 years old[Monday to Thursday]
[Monday to Thursday]
Adults: 5,000 yen / Children (elementary school age and younger): 3,500 yen [Friday-Sunday/Holidays]
[Friday to Sunday and public holidays]
Adults: 6,000 yen / Children (elementary school age and younger): 4,000 yen ● ナイトプール
大人 6,000円 ※ナイトプールは18歳以上でご利用いただけます。
-
- item
-
-
● Items for sale
- Swimsuit (women) S/M/L/LL
- Swimsuit (men) S/M/L/LL
- Swim diapers for water play (for children weighing 6kg to 20kg)
- Children's arm floats
- Children's goggles
- sunscreen
- Smartphone waterproof case
-
● Rental items: Free
- Children's arm floats
- Children's life jacket
- Inflatable ring pump
- 浮き輪
● Rental items
- Travel gown (outerwear): 300 yen (fee applies)
-
• The following facilities and services are available to you.
- Free use of the large public bath and sauna.
- Free use of the large public bath and sauna.
- Barrel sauna: Free to use
- Barrel sauna (free)
- Dedicated locker
- Changing room shower
- bath towel
- ワッフルガウン(300円)
※ご宿泊のお客様は客室にご用意しております
タオル、バスタオルもあわせてご利用いただくことにご協力をお願いいたします。
Click here for information about the public bath.
CABANA Cabana
プールサイドに設置された屋根付きのプライベートスペース「カバナ」。
日除けや休憩スペースとしてご利用いただけます。グループでのご利用におすすめです。ご予約はお電話にて、先着順で承っております。
プールサイドに設置された屋根付きのプライベートスペース "CABANA"。
日除けや休憩スペースとしてご利用いただけます。グループでのご利用におすすめです。ご予約はお電話にて、先着順で承っております。
[利用時間(枠)]
Morning 8:00~11:00(3H)
Daytime 11:30~14:00(2.5H)
Afternoon 14:30~17:00(2.5H)
Night 18:00~22:00(4H)
[ご利用時間]
14:00~22:00
[利用料金] 2名用 3,000円/枠
6名用 5,000円/枠
- Cabanas are reserved individually.
• A separate fee is required for using the swimming pool.
Refunds are not available after you have started using the cabana.
・CABANA Reservations are made per unit.
• A separate fee is required for using the swimming pool.
・CABANA Refunds are not available after the service has been used.
当日に空きがある場合は、ご利用いただけます。
• Regarding the use of our facilities by children
- おむつが取れていないお子様は、デイプールの時間帯のみ、子供用プール(水深0.4m)をご利用いただけます。必ず水遊び用パンツの上に水着をご着用ください。
- Children under elementary school age must be accompanied by a guardian to use the pool. Guardians must wear swimwear and enter the water with their children.
- When children under elementary school age use the facilities, please ensure that a guardian also wears a swimsuit and enters the water with them.
- The barrel sauna is not available for children under 12 years old.
- お子様用アームヘルパー(腕用浮き輪)や浮き輪を無料で貸し出しております。(数に限りがございます)
• Important notes regarding use
- During peak hours, we may restrict entry.
- Due to weather or safety reasons, the pool and cabanas may be closed without prior notice.
- Due to weather and safety management reasons, the pool and CABANA We may suspend operations without prior notice.
- In the event of a full-day closure, we will refund your usage fee or provide alternative arrangements. However, if restrictions on the use of the pool area are imposed only during certain hours, we will not be able to issue a refund.
- Due to weather and safety reasons, the use of inflatable rings and other play equipment may be prohibited. Please follow the instructions of the staff.
- As a courtesy to other guests, we ask that you refrain from using the pool area if you have visible tattoos (including temporary tattoos and body paint). You may only use the pool area if your tattoos are completely covered with a rash guard or similar garment.
- For safety reasons, we strictly prohibit anyone who has consumed alcohol from entering the pool. Furthermore, we reserve the right to refuse entry to anyone who is intoxicated or feeling unwell.
- For hygiene and safety reasons, bringing in food and beverages other than those intended for hydration, such as mineral water and sports drinks, is prohibited. Furthermore, to prevent injuries from breakage, bringing in glass bottles and cans is strictly prohibited.
• Regarding the use of the pool and facilities
- The adult pool has a maximum depth of 1.2m, and the children's pool has a depth of 0.4m.
- Swimsuits are not permitted inside the building or in the public baths. Please wear a top (such as a gown) at all times. Furthermore, you may not move around or enter the building in the nightwear provided in your room.
- Please note that you are not permitted to enter the restaurant in your swimwear. Please change into appropriate clothing before coming to the restaurant.
- We do not offer rentals of swimwear, goggles, rash guards, etc.
- The pool area can become very hot due to the sun. Please wear sandals in the pool area (sandals provided in your room are available for your use).
- Please be considerate when taking photos or videos, ensuring that other customers are not included in your shots.


