If you've been to a few parks with playgrounds in the Nagoya area, you've probably seen one of the concrete mountain-shaped objects like those pictured. Sometimes referred to as "Fuji-san" by residents due to the resemblance to the form of Japan's highest mountain, these are actually slides and climbing equipment. If you've seen a few, you might even think that they were common throughout Japan, but they are actually a unique feature of the urban landscape of Nagoya City and the surrounding area.
Haba Park (葉場公園), Naka Ward
Kasadera Park (笠寺公園), Minami Ward
The structure has a climbing section embedded with rocks, but more adventurous users will try to climb up the slide surface (and the less successful drift back down before reaching the top). At the top, the steep angle can make even adults feel a nervous twinge, the thrill melting away into relief as the gentler slope towards the bottom slows the descent. Kids will usually go back for more, and more again, trying to slide down head-first, backwards, and any other stylistic variation they can come up with.
Funairi Park (船入公園), Nakagawa Ward
Futase Park (二瀬公園), Nakamura Ward
One advantage of the mountain design is the added play value that the broad slide surface provides. This allows multiple people to slide at once, so kids can race one another, or even try climbing up the slide surface while other kids are sliding down, whereas the standard playground slide is designed for single-person use.
Motoshio Park (元塩公園), Minami Ward
Maruike-so (丸池荘), Minato Ward
Amid the postwar period of high economic growth, the development of residential areas in Nagoya City led to the establishment of many new parks. From the mid-1960s, several varieties of concrete playground equipment were constructed in these new parks, and also in older parks as replacements for deteriorating equipment. Although concrete equipment had been used previously, the earlier examples had mainly been one-of-a-kind, whereas the newer pieces were mass-produced from a single design.
Climbing Slider, Gotanjo Park (五反城公園), Nakamura Ward
These designs included the "Ishi no yama" (石の山 / "rock mountain"), a dome covered in rocks and other protrusions, and the "Climbing Slider" (クライミングスライダー), a structure resembling a lopsided bowl with embedded rocks and chains on the outside surface for climbing, and examples of these can still be found in Nagoya City.
The "Mount Fuji" slide design was another of those introduced around this time. While the Ishi no Yama and Climbing Slider were modelled on designs found elsewhere, the "Mount Fuji" slide, officially known as the "Play Mount" (プレイマウント), was designed by staff of Nagoya City Hall.
The first Play Mount was built in 1966, and still stands in Fukiage Park, Chikusa Ward. A jungle gym extended from the mount when it was constructed, a feature shared by a number of other later mounts; the last of these jungle gyms was removed in 2017.
While a number of Play Mounts have been removed in recent years, others have been repaired and refurbished, and new ones have also appeared.
The design has been adopted and adapted by other municipalities in the Tokai area, resulting in a multitude of variations in size and play features, including pipe tunnels and climbing nets. And slides continue to evolve as new ones appear. The slide in Handa City's Kariyado Park, completed in 2018, is the largest "Mount Fuji" slide at 14 meters in diameter and 3 meters high, and actually has stairs instead of the traditional climbing section.
Kariyado Park (雁宿公園), Handa City
Finally, a word of caution. While some newer or recently refurbished slides have a gentler, smoother surface, older slides can be quite rough and quickly wear holes in thinner fabric. Wear something durable, like denim, to avoid having to spend the rest of the day with your backside on display. Also, in hotter months, be sure to check how hot the slide is before using it.
Reference: Ushida Yoshiyuki, Nagoya no Fuji-san Suberidai (「 名古屋の富士山すべり台」), Fubaisha (風媒社), 2021 - contains a catalogue of over 120 Play Mounts and similar "Mount Fuji" slides