Kålgårdsöns nature reserve now belongs to the Archipelago Foundation. The island has no ancient remains, but cairns are scattered throughout the island.
Due to land uplift, Kålgårdsön is largely merged with Ingmarsö. The reserve includes the islands of Klippingen and Knokan and Bockholmen at Stora Rävsön. The reserve borders on Finnhamn Nature Reserve.
"In the bosom of Roslagen on the flowering island, where the waves lapping against the shore, and the reeds waving and freshly cut hay, it smells against me sometimes, there I sit on a bench in the bersong and watch terns and seagulls"