Granhammar Castle, Manor house in Upplands-Bro Municipality, Sweden

Granhammar is a manor house in Sweden featuring a three-story main building with white exterior walls and architectural details from the mid-18th century. The property includes a guest apartment building and formal gardens laid out in geometric patterns typical of that period.

Granhammar is first mentioned in writing in 1299 and belonged to Uppsala Cathedral in 1344. Its 17th-century main building burned down between 1712 and 1718, after which Hans von Fersen built new wings. The present main building was erected in 1748–1752 to drawings by Carl Hårleman for Jakob Albrekt von Lantingshausen and Anna Sofia von Fersen. In 1802–1804 Gustaf Pfeffer added a guest floor for their son Albrekt and his wife Jeanna von Stockenström.

For generations, noble families shaped this property and its grounds according to their social standing and tastes. The formal layout of gardens and tree-lined paths still reflects the lifestyle of past inhabitants.

The manor lies inside a military training and firing range taken over by the state in 1964 for Svea Livgarde, and the whole complex is a protected military object closed to the public. The former castle garden and English park are largely within the fenced area, so they cannot be visited. The building has stood empty since then, awaiting a decision on its future use.

The English park south and west of the castle was laid out from 1769 by the forester Eric Barck, who made it his life's work. A memorial stone (RAÄ Västra Ryd 34:19) honours him and urges landowners who wish to adorn their gardens to follow Eric Barck's example.