Chausuyama Dinasour Park, Dinosaur park in Chausuyama Natural Botanical Gardens, Japan

Chausuyama Dinosaur Park holds 26 life-sized models of 22 prehistoric species, made of fiberglass-reinforced plastic over steel frames, arranged by geological era. The largest is a Diplodocus 25 m long, 10 m high and 4 m wide. Built in the late 1970s and never substantially updated, the reconstructions differ from current scientific understanding.

The botanical garden opened on 27 July 1977 on a landslide scar above Shinonoi; the dinosaur park followed on 27 July 1980 as part of Nagano's 80th anniversary projects. Former city official Takehiko Kojima proposed the dinosaur theme after dreaming of dinosaurs on the slope. The models were built by Nitto Shoji, and eight more were added in 1981.

The park's name comes from Chausuyama hill, where a landslide destroyed apple orchards before the site was redeveloped. The dinosaur theme was proposed by Takehiko Kojima, a former Nagano city official, who argued that dinosaurs, unlike fictional monsters, were real creatures of Earth's long history. Models are grouped by geological era, from the Permian through the Jurassic to the Cretaceous.

The park is free to enter and closes from mid-December to mid-March because of snow. Of the 464 free parking spaces, lots 1 to 6 and the north lots close at night (17:00-8:30) and in winter, while lot 7 stays open at all times. From Shinonoi Station, reached by JR and Shinano Railway, the park is about 15 minutes by taxi.

The largest model is the Diplodocus, 25 m long, 10 m high and 4 m wide. Because the park stands on a landslide area where concrete foundations were not allowed, the figures rest on raft-like steel frames of H-beams, and their fibreglass-reinforced plastic skins, with 20 percent glass fibre and internal steel, are built to withstand winds of 30 to 35 m per second.