Alstavik, Manor house on Långholmen, Sweden

Alstavik is a two-storey Baroque manor with a three-storey frontispiece, built on Långholmen's south side. Its facades once had columns and painted window decorations, and a monumental open staircase with rose beds stood in front. A separate kitchen wing was added to the northwest. The original interior ceilings were richly painted; some murals survive under the plaster, found during repairs in 1967 and 1983.

Jochum Ahlstedt, a court brewer from Lübeck, acquired a central plot on Långholmen's south side in 1667 and completed the Alstavik manor in 1670, the island's first stone building. In 1724 the Kommerskollegium bought it for a women's spinning house; a spinning-house wing was added in the mid-1700s. From 1825 it formed part of Långholmen Central Prison, which closed in the 1970s.

The name Alstavik survives in Alstaviksvägen and the Alstavik block on Långholmen. Since 2010 the building has housed Långholmens Wärdshus and the pub Finkan, whose name means "the cell" in Swedish.

The site is accessible via two bridges connecting the island: Pålsundsbron from the east and Långholmsbron from the west. The location works well for walks since paths and open areas surround the manor.

The 1688 Gripenhielm map shows Alstavik beside Heleneborg across Pålsundet, with Ahlstedt's angled main building, his malthouse to the left and a three-chimney building with a thatched roof to the right. Painted inner ceilings survive under the plaster, found during repairs in 1967 and 1983.