Overview

Resol no Mori is a large forest resort on the Boso Plateau in Chiba, close enough for an easy escape from Tokyo. You trade city noise for trees, lawns, hot springs, pools, sports grounds, and open-air activities across a wide resort area. The main access is simple: about 5 minutes by car from Itakura IC or Mobara-Nagara Smart IC, or about 20 minutes by free shuttle bus from JR Honda Station.

This is not a traditional ryokan, but it gives you a nature-led onsen stay with many Japanese resort comforts: natural black hot spring bathing, semi-natural spa baths, glamping, suite-style hotel rooms, log cottages, private dog-friendly villas, BBQ dining, Japanese kaiseki, sports, pools, and forest activities. The resort’s official pages present it as an experience-focused resort with sports facilities, restaurants, spas, and stays spread through the forest.

Accommodation

You choose more than a room here; you choose the style of your stay. Resol no Mori offers glamping tents, terrace houses, terrace house premium units, Hotel Trinity Shosai suites, log cottages, a campsite, and dog-friendly villas at Dear Wan Spa Garden.

At Grandvaux Spa Village, you can stay close to the forest in a Tent Cabin, Tent Cabin Premium, Glamping Villa, Terrace House, or Terrace House Premium. The Tent Cabin has a private terrace and a skylight window, with beds, amenities, tools, and BBQ food prepared for you. The Tent Cabin Premium connects a bedroom tent and living-room tent, giving you more space and access to a deck terrace. The Glamping Villa is a two-person villa with a bedroom, wooden deck terrace, bath, refrigerator, toilet, Wi-Fi, air conditioning, and bathroom amenities.

The Terrace House gives you an indoor space and outdoor living area, with a flat terrace and outdoor dining space for BBQ or relaxed meals. It includes a bath, TV, kettle, tea set, air cleaner, refrigerator, hair dryer, toilet with washing function, air conditioning, Wi-Fi, towels, sleepwear, slippers, and bath amenities. The Terrace House Premium adds a larger residential-style layout with a living room, kitchen, terrace, and kitchen tools, so it suits longer stays or small-group trips.

For a hotel-style stay, choose Hotel Trinity Shosai, the 16-story symbolic tower of Resol no Mori. All rooms are suites with separate living and bedroom spaces, a Japanese-style Shosai desk for reading or work, and views across the forest. Room choices include the 126-square-meter Premium Suite with two twin bedrooms and one Japanese-style room, the 80-square-meter Relaxation Suite with one twin bedroom and sofa bed, and the 62-square-meter Suite for two. All rooms are non-smoking and include a TV, refrigerator, kettle, bath, toilet with washing function, hair dryer, air cleaner, air conditioning, sleepwear, towels, slippers, and bathroom amenities.

Choose a Log Cottage when you want a full cottage stay with your group. These hinoki cypress log cottages were renewed in April 2020 and come in layouts for 4 or 8 people. You have a center living space, private twin rooms, a kitchen for preparing meals, and private rooms with bath and toilet. Cooking utensils can be rented, and plates and cups are already provided.

If you travel with your dog, Dear Wan Spa Garden gives you a private villa with black natural hot spring water in every villa. Villa Twin has 52 square meters of indoor space, a 44-square-meter deck terrace, and a private dog run of at least 135 square meters. Villa Fourth has 70 square meters indoors, a 44-square-meter deck terrace, and a private dog run of at least 160 square meters. You also have dog-friendly features such as a private dog run, pet camera, dog guard, welcome treats, dog amenities, dog bed, microwave, refrigerator, water server, air purifier, raised outlets, foot-washing area, and delivery box.

Dining

Dining depends on your accommodation and plan, but the resort gives you strong choices across Japanese dining, BBQ, buffet-style meals, cafés, bars, and golf-course restaurants. The official restaurant page highlights food from the Boso Peninsula, including seafood, local produce, and mountain ingredients.

For Japanese dining, Suisutei is one of the resort’s most distinctive restaurants. This building was moved from the former Swiss Embassy and is listed on the official page as a Registered Tangible Cultural Property. You can enjoy lunch or reservation-only dinner in a Japanese setting facing a dry landscape garden. Lunch is usually 11:00 a.m. to 2:00 p.m., and dinner is 5:00 p.m. to 9:00 p.m. with reservation required.

For a glamping stay, dinner can be outdoor BBQ with tools and ingredients prepared for you. The official Grandvaux page highlights Chiba’s Shiawase Kizuna Beef and fresh Boso seafood, while current plan pages mention BBQ served from 5:00 p.m. and a morning box with local fresh vegetables, soup, omelet, and other breakfast items.

Restaurant Sport, inside the Medical Training Center, serves an Eatwell-style buffet supervised by a registered dietitian. It focuses on practical, sustainable eating and is open for lunch, with weekday and weekend/holiday hours listed on the official restaurant page. Dear Wan Terrace is a dog-friendly café with a dog run, lunch dishes, sweets, and food for dogs.

You can also enjoy BAR Momiji inside Grandvaux Spa Village, with Swiss wines and a calm post-bath setting. THE GRILL Manna sits inside the Manna Country Club clubhouse and serves lunch using Chiba ingredients. The resort also has Trinity Shop, Lac Leman Shop, Grandvaux Shop, and MTC Shop for drinks, snacks, souvenirs, pool goods, and sports items.

Onsen and Wellness

Resol no Mori has two main bathing styles: the natural hot spring at Momiji no Yu in Grandvaux Spa Village and the semi-natural Nagara Karuna no Yu inside the Medical Training Center.

Momiji no Yu is the main natural hot spring. The water rises from about 600 meters underground and is a dark brown sodium hydrogen carbonate mineral spring. The official pages describe it as weak alkaline black water with a soft feel, often associated with smoother skin. The bath area includes indoor and open-air hot spring baths, and the Grandvaux page lists the spring as a low-temperature sodium hydrogen carbonate spring with benefits including neuralgia, muscle pain, joint pain, wounds, poor peripheral circulation, sensitivity to cold, and dry skin.

Nagara Karuna no Yu is a semi-natural hot spring bath using mineral stone from Hokkaido’s Futamata Onsen. It includes cloudy white bath water, a carbonated bath called Ramune no Yu, and saunas for both men and women. The men’s bath has a semi-open-air bath, while the women’s bath was expanded to 1.5 times its former size. Listed benefits include relief for heat rash, rough skin, sensitivity to cold, eczema, chilblains, bruises, sprains, rheumatism, fatigue, stiff shoulders, lower back pain, neuralgia, and hemorrhoids.

For pool time, Lac Leman Pool is an outdoor resort pool shaped after Lake Geneva, with a total length of 130 meters. The indoor pool is a heated 25-meter pool with six lanes and floor heating, so you can swim regardless of season or weather.

For spa treatments, Spa Jour Ferie offers relaxation in a salon overlooking the forest, using organic essential oils. The resort also lists wellness retreats for longer stays focused on the body and mind.

Guests with Tattoos

People with tattoos cannot use the spa or sauna. For Momiji no Yu day-use information, the official page says tattoos must be covered with a dedicated sticker, and the sticker is sold at the bar. Rules may differ by facility and stay plan, so confirm with the resort before using shared baths or saunas.

Facilities

You gain access to a wide range of facilities spread across the resort grounds:

• Indoor and outdoor swimming pools
• Spa and sauna areas
• Tennis courts and golf facilities
• Fitness and training spaces
• Mini golf and outdoor recreation zones
• Shops, cafés, and restaurants
• Event and meeting spaces
• Shuttle service and parking

Because everything sits within the same resort area, you move easily between rest and activity throughout the day.

Activities

You can make your stay as active or as quiet as you like. The inclusive-experience page lists forest activities such as the 445-meter Long Zip Slide, Forest Adventure Tarzania Kids Course, mini golf, summer Lac Leman Pool, tennis, a 400-meter green track, Nordic walking, futsal, and disc golf.

The indoor activity list is also strong for rainy days. You can use the 25-meter indoor heated pool, obstacle course, bouldering wall, table tennis, sponge tennis, basketball, badminton, unicurl, indoor 200-meter track, kids’ exercise area, and fitness machines, depending on eligibility, hours, and availability.

At Grandvaux Spa Village, you can enjoy wood chopping, BBQ, Momiji no Yu, BAR Momiji, a bonfire, morning yoga, hammocks, herb picking, fresh herbal tea, cycling, SUP, Tarzania, and first-time horse riding experiences

Additional Features

Resol no Mori also works well for special occasions. You can host events, retreats, or celebrations within the resort’s large open spaces and dedicated venues. Seasonal decorations and programs add character throughout the year, giving your stay a sense of timing and place.

By the time you leave, you feel rested, refreshed, and re-energized—without feeling rushed or overwhelmed. Resol no Mori gives you space, choice, and comfort, all wrapped into one expansive forest retreat.