Grand Mercure Minamiboso Resort & Spa (1212 Tatara, Tomiyura-machi, Minamiboso City, Chiba; General Manager: Shunpei Mizuno), located on the Taibusa Misaki (大房岬) headland within the Minamiboso Quasi-National Park overlooking the Pacific Ocean, is rolling out 10 hands-on summer experiences for families in 2026. The lineup spans an all-inclusive outdoor pool, a giant inflatable truck slider, yoga by the sea, stargazing, campfires, a sunset cape tour, a planetarium visit, an ocean plastics workshop, and more — letting guests not just see the natural scenery of Minamiboso but touch, learn, and play in it.
1. All-Inclusive Outdoor Pool
The outdoor pool reopens this summer for another season of family-friendly resort relaxation. Guests can enjoy the open-air setting with sunlight and sea breezes, and a shallow wading pool with a depth of approximately 40 cm is available for young children just starting out in the water.
Period: Saturday, July 18 – Wednesday, September 23, 2026
Hours: 9:00 AM – 5:00 PM (available before check-in and after check-out)
Pool depth: Approx. 105 cm (main pool); approx. 40 cm (children's shallow area)
Reservations / Price: No reservation required; included in accommodation rate. Day-use not available.
2. Giant Truck Slider (New)
A large inflatable truck slider makes its summer debut. Guests climb up the inflatable structure and slide down in one exhilarating run — the kind of activity kids want to repeat over and over. Because it is set up indoors, it is unaffected by rain.
Dates: Monday, August 3 – Friday, August 7, 2026
Hours: 1:00 PM – 6:00 PM
Venue: Hotel 1F
Reservations / Price: No reservation required; included in accommodation rate.
Note: Content may be changed or cancelled without notice.
3. Air Trampoline and Badminton
An air trampoline and badminton court give kids a chance to burn off summer energy with large physical movements.
Dates: Monday, August 3 – Thursday, August 20, 2026
Hours: 1:00 PM – 6:00 PM
Venue: Hotel 1F
Reservations / Price: No reservation required; included in accommodation rate.
Note: Content may be changed or cancelled without notice.
4. Campfire (Hotel Area)
A summer-only campfire evening features games and singing around the flames. Gathering around the fire with family or friends makes for a memorable part of any trip, surrounded by the open nature of Minamiboso.
Dates: Tuesday, August 4 and Tuesday, August 25, 2026
Hours: 7:00 PM – 8:00 PM
Venue: Beside the hotel chapel
Reservations / Price: No reservation required; included in accommodation rate.
Note: May be cancelled due to weather. Comfortable clothing recommended.
5. Sunset Taibusa Misaki Tour (Coastal Area)
A guided tour explores the Taibusa Misaki headland at dusk. Participants enjoy a hammock experience and nature discovery activities while learning about the natural environment as "Kids Rangers."
Dates: Sunday, August 9; Thursday, August 13; Thursday, August 27; Sunday, August 30, 2026
Hours: 5:00 PM – 6:30 PM
Price: ¥1,500 per person (tax and service charge included)
Capacity: 10 participants
Eligible participants: Elementary school age and under (parents/guardians must accompany)
Reservations: Required — call the hotel main line at 0470-33-3811
Note: Content may be changed or cancelled due to weather.
6. Parent-and-Child Stargazing (Hotel Area)
Guests use a telescope to observe the clear night sky over Minamiboso, getting a close look at stars and the surface of the moon that are hard to see with the naked eye. Hotel staff narrate the session, making it enjoyable for both children and adults.
Dates: Saturday, August 22; Friday, August 28; Saturday, August 29, 2026
Hours: 7:45 PM – 8:15 PM
Reservations / Price: No reservation required; included in accommodation rate. Drop-in participation welcome during the session.
7. Sunset Terrace (Hotel Poolside)
Guests can recline in lounge chairs on the poolside terrace, feeling the sea breeze as they take in the sunset and night sky. The view of stars filling the sky above creates an otherworldly atmosphere far removed from everyday life.
Dates: Saturday, August 1 – Monday, August 31, 2026
Hours: 7:00 PM – 9:00 PM
Reservations / Price: No reservation required; included in accommodation rate. Drop-in welcome during the session.
8. Yoga by the Sea (South Lawn Area)
A beginner-friendly yoga session takes place on the open lawn with a view of the Minamiboso sea. Stretching slowly while feeling the sea breeze refreshes both body and mind. An instructor provides gentle guidance throughout, so first-timers and guests with children can participate with ease.
Dates: Sunday, July 19; Sunday, August 2; Tuesday, August 11; Wednesday, August 19, 2026
Hours: 9:00 AM – 10:00 AM (meet in the lobby at 9:00 AM)
Price: ¥1,000 per person (tax and service charge included)
Capacity: 15 participants
Eligible participants: Age 10 and over (elementary school age and under must be accompanied by a parent/guardian)
Reservations: Required — call the hotel main line at 0470-33-3811
Note: Venue may change due to weather.
9. Planetarium (Minamiboso City Taibusa Misaki Nature House Area)
A staff guide explains the constellations visible in each season and the appeal of the local night sky in an easy-to-follow way. Suitable for children and adults alike, this experience also works well as a summer holiday research project.
Date: Sunday, August 16, 2026
Hours: 7:00 PM – approx. 8:15 PM (meet in the lobby at 7:00 PM)
Price: Included in accommodation rate
Capacity: 60 participants
Reservations: Required — call the hotel main line at 0470-33-3811
10. Ocean Plastics Workshop (Hotel Indoor)
A workshop where participants learn about the impact of ocean plastic on marine environments and the challenges the ocean faces today, then use actual recovered materials to create an item. Getting hands-on with environmental issues through play makes this a natural fit for a summer holiday project.
Dates: Thursday, August 13 and Friday, August 14, 2026
Hours: 9:00 AM – 12:00 PM
Venue: Hotel 1F
Reservations / Price: No reservation required; included in accommodation rate. Drop-in welcome during the session.
Family-Friendly Guest Rooms
Classic Family Twin — Forest View
The Classic Family Twin Forest View is certified under the "Welcome Baby Inn" program and comes pre-stocked with a range of amenities and equipment for families with young children.
Room size: 36 m²
Maximum occupancy: 5 guests (including 2 sharing a bed)
Included equipment and amenities: Microwave, milk-warming pot, children's slippers, baby soap, baby bath, diaper bin, baby wipes, bottle-washing set (dedicated detergent and brush), baby chair, children's toilet seat, step stool, baby bed
Other family-suitable room types include the Classic Comfort Triple, Classic Comfort Twin (Japanese-Western), and Standard Junior Suite Forest View.
About the "Welcome Baby Inn" Certification
Grand Mercure Minamiboso Resort & Spa holds "Welcome Baby Inn" certification from the Miki House Child-Rearing Research Institute. The certification evaluates facilities and services across 100 criteria covering both hardware (equipment) and software (hospitality and service menus) to ensure the property meets a defined standard for families traveling with young children. As of April 2026, the number of eligible rooms expanded from 2 to 4.
Hotel Facilities
Kids Activity Area "Asobiba"
An indoor kids area for children aged 2–6, featuring rounded-edge wooden furnishings for safety. The space includes picture books, toys, and seating for accompanying adults. Free for hotel guests.
Hotel Information
Grand Mercure Minamiboso Resort & Spa is a resort hotel within the Minamiboso Quasi-National Park, surrounded by lush greenery. It offers easy access from the greater Tokyo area, a restaurant serving signature menus using local ingredients, a large public bath with an outdoor bath and sauna, and a kids' space.
The all-inclusive accommodation rate covers lounge access. The "楽遇 / EVENING SOCIAL" (3:00 PM – 6:00 PM) offers sparkling wine, beer, coffee, tea, herb water, and other drinks, while the "鳥渡 / NIGHT CAP" (7:00 PM – 11:00 PM) features local specialty snacks and a bar. Dinner and breakfast are served buffet-style and alcoholic beverages are included. Dinner highlights include local Boso seafood dishes; breakfast highlights include local Boso seaweed and regional specialties.
Address: 1212 Tatara, Tomiyura-machi, Minamiboso City, Chiba 299-2404
Reservation Center: 03-5539-2634
Website: https://grand-mercure-minamiboso-resortandspa.jp/
Access: Approx. 8 min by car from Tomiyura IC on the Tateyama Expressway; approx. 10 min by taxi from JR Tomiyura Station
Price: All-inclusive from ¥26,000 per person per night (based on 2 guests sharing a room, tax and service charge included)
Note: Some drinks and activities are not included. Lunch is not provided. Menu contents and sourcing may change seasonally.
New Menu at the Dinner and Breakfast Buffet
On April 1, 2026, Grand Mercure Minamiboso Resort & Spa celebrated its 2nd anniversary. The buffet restaurant "Le sensoriel" launched a new set of signature menus inspired by the concept of a "marché" (market), featuring the excitement of discovery, the energy of live-kitchen cooking in front of guests, and the freshness of experiencing local flavors in a travel setting. Vegetarian menu options have been expanded, and the children's menu has been enhanced as well.
