Begonia Greenhouse, Nikkō Hana-ichimonme (日光花いちもんめ 大温室)

The venue is a private business at Kosagoe in the Kinugawa valley, between the hot-spring station of Kinugawa-Onsen and the Edo Wonderland theme park, whose buses stop at "Hana-ichimonme" outside the gate. A Hoshino Resorts travel guide notes that one begonia has flowered without interruption since the opening, twenty-five years as of 2026. The same guide adds that the director comes from a farming family, which fits the dual character of the place, part display garden and part working nursery.

Around the main begonia greenhouse, which the venue bills as the largest begonia garden in Kantō and northern Japan, seasonal attractions have accumulated: a strawberry house open for picking from mid-December into early summer, then again in June and July with summer varieties, an outdoor dahlia garden of 400 varieties from August to November, and a viola garden of 60,000 plants that opened on 20 March for the 2026 season. Tourist guides disagree on the size of the collection: 600 cultivars and 5,000 pots according to Rurubu, 250 kinds or 600 cultivars and 8,000 pots on Jalan's pages, while the official site counts about 3,800 pots on show in the main greenhouse.

The main greenhouse, labelled "Building A" on the official plan, is 90 metres long and 20 metres wide, dimensions confirmed by its footprint on the map, an elongated north-south rectangle a few dozen metres from National Route 121. The walls are glazed, according to the Hoshino Resorts guide, which describes the visitor stepping into "a large glass greenhouse" full of colourful begonias. Because begonias come from the Andes, the air is kept between 15 and 25 °C all year, cool in summer and mild in winter, which also makes the place a rainy-day option.

Inside, the layout is that of a display hall: tiered benches carry a standing stock of about 3,000 upright begonias, while some 800 baskets of trailing begonias, the longest of them over 2 metres, hang above the aisles, and a small café sits in the middle of the nave. A second, smaller building holds seasonal flowers, a 5-metre flower tower, foliage plants and the small-animal corner.

Begonias make up most of the collection: tuberous begonias, which dominate the main greenhouse and some of whose flowers exceed 20 centimetres across according to Rurubu, trailing begonias in hanging baskets, single and double forms in white, pink, orange and red, with round or heart-shaped leaves, plain or variegated. The official site adds moth orchids (kochōran) in flower all year, in white, pink, purple and red. Outdoors, clematis bloom from mid-May to mid-June, violas from mid-March to mid-May and the dahlias, 400 varieties and 2,000 plants, from mid-August to early November, some flowers more than 30 centimetres wide. The strawberries picked on site are of the varieties Tochiotome, Yayoihime, Skyberry and Tochiaika in winter and spring, then Natsuotome, Suzuakane and Yotsuboshi in summer.

Allow an hour for the main greenhouse, the animal building and the flower shop, more with strawberry picking, which must be booked, or the dahlia garden, each charged separately. The greenhouse can be visited all year; autumn pairs begonias with dahlias, spring begonias with violas. The "Hana-ichimonme" bus stop is served from Kinugawa-Onsen Station by the line that carries on to Edo Wonderland and Tōbu World Square, two theme parks in the same district; Kosagoe Station is a quarter of an hour away on foot. Dogs are admitted provided they are carried or in a stroller.