Vanilla Dome, Tropical Plant House of Ibaraki Botanical Garden (バニラドーム／茨城県植物園 熱帯植物館)

Ibaraki Botanical Garden (茨城県植物園) was opened by Ibaraki Prefecture in 1981 in the To district of Naka. Covering about 12 hectares, it was meant both to spread knowledge of plants and to offer a place of rest. It sits beside the prefectural forest (茨城県民の森), which extends over 64.7 hectares, a forest culture centre and a mushroom museum, the きのこ博士館, so that together they form a cluster devoted to the natural world.

More than forty years after it opened, the site was given a complete overhaul. The garden closed in June 2024 according to Japanese Wikipedia, in July according to the local press; before it shut, flowers lifted from its beds were handed out to visitors at several events. Operation was then entrusted to a private special-purpose company, tasked with adding accommodation, hot-spring baths and restaurants.

A reopening ceremony took place on 27 November 2025, and the public returned from 29 November under the name THE BOTANICAL RESORT 林音 (Rinne), presented as the first botanical garden in Japan where visitors can stay the night. Entry is still free, with charges only for the facilities, and the stated target is 380,000 visitors a year by 2030. The tropical plant house was refitted for the occasion and renamed the Vanilla Dome.

The sources consulted name neither the architect nor the construction year of the tropical plant house, and they describe neither its frame nor its glazing. A travel guide gives it a floor area of 2,694 m², making it one of the larger display buildings in the garden.

The 2025 refit reorganised the interior into five zones: an entrance area followed by four recreated habitats, farmland, wetland, jungle and hill country, which echo the places the plants come from. A viewing room and a set of stairs let visitors look at the vegetation from several heights rather than from ground level alone.

A café was fitted into the building, and a lighting, smoke and music installation turns the house into a night-time stage set for guests staying on the estate. The word dome in the new name comes with no detail in the sources about the shape or the materials of the envelope.

The Vanilla Dome holds around 240 species and some 23,000 plants from the tropical and subtropical regions of Southeast Asia. Vanilla takes the leading role: more than fifty vines were added during the refit, and the café inside the house turns the spice into crêpes and soft-serve ice cream.

The official site also names frangipani, petrea, the カエンボク, a tree with flame-coloured flowers, the ヒスイカズラ, a climber with jade-green flower clusters, and the fragrant shrub ニオイバンマツリ. Before the works, guides already singled out the scented ylang-ylang tree and the bottlebrush (ブラシノキ) among the notable plants. Displays of night-flowering plants are planned through the year. According to its staff, the garden as a whole grows about 600 species.

The house stands within the garden, which is free to enter, and a visit combines easily with the neighbouring prefectural forest and the mushroom museum. Staff lead guided walks on plant ecology and horticultural techniques.

The night-time shows inside the house, with light, smoke and music, are reserved for guests who sleep on site, in glamping tents or cottages. The estate also offers a hot-spring bath, a 150-metre zip line and a tree-canopy walk. Meals are served at an Italian restaurant and a food hall within the grounds.