[2] Bad Wilhelmshöhe [de], a Stadtteil of Kassel in northern Hesse, is situated west of the city centre at the foot of the Habichtswald hill range.

The park comprises an area of about 2.4 square kilometres (0.93 sq mi), stretching from Kassel up to the Karlsberg mountain at 526.2 metres (1,726 ft).

In 1143, Canons Regular from Mainz established the Weißenstein monastery at the site of present-day Schloss Wilhelmshöhe, which was dissolved in the course of the Protestant Reformation.

In 1701, the Italian architect Giovanni Francesco Guerniero [de] started the construction of the Hercules monument and the giant cascades.

In 1785, Wilhelm (William) IX, Landgrave of Hesse started a large extension of the park, and the following year his architect, Simon Louis du Ry, designed the Neoclassical palace Schloss Wilhelmshöhe.

In the course of the extension and modifications, Heinrich Christoph Jussow [de], apart from contributing to the design of the palace, created constructions still characterizing the park today: artificial ruins like the Löwenburg [de] (Lion's Castle) and the Roman aqueduct, as well as extensions of the water garden like the Lac, the fountain pond, and the Teufelsbrücke (Devil's Bridge) with the Höllenteich (Hell's Pond).

Kassel became the capital of the newly created Kingdom of Westphalia, a vassal state of France, ruled by Napoleon's brother Jérôme Bonaparte.

In 1826, William II, Elector of Hesse ordered the last large construction of the Bergpark Wilhelmshöhe, the grosser Wasserfall (Great Waterfall).

From 1899, German Emperor Wilhelm II, who went to school in Kassel, chose Wilhelmshöhe as his summer residence, which turned the castle and the park into a centre of European politics for the next two decades.

Art historian Georg Dehio (1850–1932), inspirator of the modern discipline of historic preservation, described the park as "possibly the most grandiose combination of landscape and architecture that the Baroque dared anywhere" ("vielleicht das Grandioseste, was irgendwo der Barock in Verbindung von Architektur und Landschaft gewagt hat.").