Björnö nature reserve, Nature reserve in Kalmar Municipality, Sweden

Björnö nature reserve is a protected area in Kalmar Municipality featuring forests, wetlands, and coastal zones. The varied habitats support numerous plant and animal species adapted to these different conditions.

Björnö is first mentioned in 1346, when nobleman Bengt Myrk dated a letter there. In 1458 the estate passed to Birgitta Gustavsdotter (Sture), and it then comprised 66 farms, four mills and about ten farms on Öland. The medieval manor declined into ordinary noble farms until Carl Eriksson Oxenstierna re-established it as a säteri in 1609. Carl Otto Posse built the present main building on the old foundations in 1850 and an orangery in 1858; the estate was sold in 1885 and became a nature reserve.

The manor house displays traditional Swedish building style with features reflecting regional heritage. The structure gives visitors a sense of how people lived in this area in earlier times.

The manor lies in Åby parish in Kalmar Municipality, with the surrounding area now a nature reserve. The reserve is reached by road from Kalmar, and the grounds around the manor can be explored on foot. The buildings themselves are not open to the public; the estate has been leased to Björnö Slott Hälsohem since 1973.

The manor house at the center demonstrates how human settlements once coexisted with surrounding nature. This historic structure represents a time before nature and human use became sharply divided.