The mountain you climb for the udon
Mt. Nabewari (1,273 m / 4,176 ft) sits at the southern end of the Tanzawa range, on the border of Hadano City, Matsuda Town, and Yamakita Town in Kanagawa Prefecture. It connects by ridge to Mt. Tonodake (1,491 m) and forms part of the same massif as Mt. Tanzawa (1,567 m) — a familiar weekend destination for Tokyo-area hikers. But Nabewari has a more specific draw than its neighbours: the summit hut serves hot-pot udon, and for most weekend visitors, climbing the mountain and eating that udon are two parts of the same activity.
The summit is a long, flat north-south clearing — among the most open summit platforms in the Tanzawa range — with a sweeping view south-west to Mt. Fuji and Sagami Bay. Local hikers also call the mountain San-no-kaya, a folk name that survives alongside the official one. At 1,273 m it is a mid-grade Japanese mountain, but with about 1,000 m of vertical gain from the Ōkura trailhead and roughly four hours up, the climb is more substantial than the casual reputation suggests.
Routes
The standard ascent runs from Ōkura trailhead (290 m) along the Nishiyama forestry road to Futamata (540 m, about 80 minutes), then up over Ushirozawa-nokkoshi col to the summit in another 2h30. At Futamata, you will encounter the most distinctive piece of Tanzawa hiking culture: a pile of 2-litre water bottles waiting to be carried to the summit hut. No one asks you to take one, but most regulars carry one or two — the hut has no on-site water, and the entire mountain's hot-udon production runs on these voluntarily-portaged bottles.
An alternative route is the Yadorigi route from Yadorigi bus stop (290 m) via Mt. Kunugi and Kuri-no-ki-dō, joining the main ridge at Ushirozawa-nokkoshi (3h30 to summit) — longer than Ōkura but with quieter forest. For a fuller day, the Nabewari → Komaru → Ōmaru → Tonodake traverse adds 2 hours of ridge walking to Tonodake; the full Ōkura-Futamata-Nabewari-Tonodake-Ōkura loop is 7–8 hours and considered the canonical Tanzawa-south day hike.
Access from Tokyo
From Shinjuku, the Odakyū Line reaches Shibusawa Station in about 80 minutes; the Kanachū bus from Shibusawa to the Ōkura trailhead takes 15 minutes. Leave Shinjuku by 6:30 a.m. and you're on the trail by 8:30 — in time for the udon order cutoff at the summit hut, which typically falls around 14:00 (but can be earlier if the hut sells out). For the Yadorigi route, take the Odakyū Line to Shin-Matsuda Station and the Fuji-kyū Shōnan bus to Yadorigi (25 minutes). Drivers park at the Hadano-Tokawa park complex near Ōkura (200+ cars); the lot fills before 7 a.m. on autumn weekends.
Nabewari-sansō hut and the water-portage tradition
On the east side of the summit stands Nabewari-sansō, the hut whose udon defines the mountain. It is operated year-round by Nobutaka Kusano, who in the 1980s participated in Himalayan expeditions to Aconcagua, Satopanth in the Indian Himalayas, and Dhaulagiri I — an unusual professional background for a Tanzawa hut keeper. The Nabewari nabe-yaki udon is a single steaming hot-pot of noodles with egg, tempura, fried tofu (abura-age), shiitake mushroom, naruto fishcake, leek and spinach in a carefully prepared dashi, served on benches with Mt. Fuji directly in front. For many Tokyo-area beginners, eating it at the summit is something of a rite of passage.
The hut has no on-site water source. Instead, Tanzawa hikers carry water up themselves, picking up a 2-litre bottle from the pile at Futamata as they pass through. No one is required to participate, but the system works because most regulars do — the practice is one of the few entirely-voluntary mutual-aid customs in Japanese mountain culture. When you reach the summit and the hut owner thanks you for the water you brought, the udon really does taste different. This is the unofficial reason many people climb Nabewari more than once.
The summit view
The summit is a long, north-south flat clearing with many benches and tables. On a weekend at midday, more than a hundred hikers can be eating udon along the platform at once. The view opens south and south-west: Mt. Fuji directly opposite across the foothills, Sagami Bay and the Shōnan coast to the left, and on very clear days, the Izu Peninsula's mountainous spine in the distance. Tonodake (next ridge over, about 2 hours away) offers a wider 360° panorama, but Nabewari trades the 360° view for a flat, open, sunny summit that holds its warmth even in mid-winter.
January and February clear days are the best time to see Mt. Fuji from Nabewari: cold dry high-pressure air gives near-daily clarity, and a snow-capped Fuji directly opposite the summit ranks among the best Fuji-view-from-Kantō shots available without a longer trip.
What to bring
Despite the casual 'udon mountain' reputation, treat Nabewari as a real 1,000-metre climb. Mid-cut hiking boots, a 20–30 L pack, long sleeves, light fleece and a packable rain shell. If you plan to portage a water bottle to the hut, budget for the extra 2 kg in your pack. Standard climbing season is year-round. Best windows: late April (new green), early November (foliage), and January–February (Mt. Fuji clarity). Microspikes are useful from December through March — frost and patchy ice form regularly above 1,000 m even when there is no real snowpack. Summer is hot and humid in the lower valley with yamabiru (mountain leeches) active below 800 m; gaiters or knee-high socks are advised. Nabewari-sansō sells udon, coffee and snacks, so heavy food provisions are unnecessary — but carry a backup snack in case the udon has sold out for the day.
The Nabewari udon is not 'tourist food' once you actually try it. The ingredients are generous, the broth carefully prepared, and the hut's operation — boiling noodles, warming broth, cracking eggs to order for several hundred customers per weekend, year after year — is the sort of low-rotation small-scale culinary craft that has effectively disappeared from urban Japan. Hours and stock levels vary; check the hut's site or SNS before the morning of your climb.
What's next in Tanzawa
From Nabewari, the natural next objective along the ridge is Mt. Tonodake — about 2 hours along the crest via Komaru and Ōmaru. Tonodake offers a true 360° view including the Southern Alps and the Yatsugatake range. A full day combining Nabewari and Tonodake before descending the Ōkura ridge is the classic intermediate Tanzawa-south route. Further north, Mt. Tanzawa (1,567 m, the 100 Famous Mountains peak that the Tanzawa range is named after) sits another 2 hours beyond Tonodake — a possible overnight from Miyama-sansō. To the west, Mt. Hinokibora-maru (1,601 m) is a peak with one of greater Tokyo's most photographed azalea blooms in late May. Climbing Nabewari is, in this sense, both an end in itself and a gateway: the lightest day in the Tanzawa range that still teaches you what hiking in this corner of greater Tokyo feels like.
