Castle Buonas

Castle Buonas stands on a peninsula of the Zugersee in the Buonas quarter of Risch, Switzerland, and was established in the medieval period by local knightly families.

A carved date above the castle portal records 1071, and the place name first appears in a donation charter of 22 January 1130 that names knights “von Bochunna.” Individuals tied to the castle appear in later records, including Petrus de Buochnase in 1223. In 1250 Adelheid of Buonas, the last member of her line, married Ulrich von Hertenstein, and the property passed into the Hertenstein family. Over time the site has been known by several names, including Burg Buonas, Schloss Hertenstein, and Altes Schloss Buonas.

Tensions over legal authority around the castle led to a confrontation in the early 15th century. In 1421 military action was threatened between the canton of Zug and the Hertenstein family. An arbitration meeting on 20 August 1424 assigned lower-court jurisdiction to the Hertensteins while reserving highest jurisdiction to the canton of Zug. Destruction struck the castle in 1478 when it burned down to its foundations. Work to rebuild began in 1494 and finished in 1498, at which time the reconstructed building received an extra storey.

The Hertenstein line ended as local lords when the last heiress married Johann Martin Schwytzer in October 1654 and conveyed the estate to him. On 28 March 1782 Josef Xaver Thüring Schwytzer sold the castle for 37,625 Gulden to two citizens of the city of Zug, with two thirds of the purchase amount financed by the city. The property then passed through a number of owners and fell into neglect until 1862, when Count Mieczislaw de Komar of Paris bought the estate and carried out an extensive restoration.

In 1871 Carl August von Gonzenbach-Escher acquired the grounds, laid out the park landscape, and from 1873 to 1877 commissioned the English architect William Wilkinson to erect a large neo‑Gothic villa known as the New Castle. The villa stood in the park after its completion in 1877; one account records its presence there until 1979, while another record states it was demolished in 1970 and replaced by a country house. That demolition drew criticism from the Federal Commission for Monument Preservation and from the ETH Zürich architectural historian Paul Hofer, and the cantonal building authority did not reverse the decision. The loss of the villa is regarded locally as one of the canton’s greatest losses of architectural substance and led the canton of Zug to appoint a full‑time monument and conservation officer.

In 1997 the Basel pharmaceutical firm Hoffmann‑La Roche purchased the castle complex to create a management training center called the Roche Forum, and committed to preserving the historic buildings and the surrounding landscape.